Fifteen years ago it was unfathomable – and a bad idea – to imagine that your digital messages could automatically self-destruct.. Once your message is on someone else’s machine, you simply cannot guarantee that it will be destroyed when you want it to be. Fooling people into thinking they have more security and privacy than they really do can put them in harm’s way.

Today, however, modern messaging apps have built exactly this feature. Signal Private Messenger, WhatsApp, SimpleX Chat, DeltaChat, and Facebook Messenger all have a disappearing messages function. Wire has self-deleting messages, Telegram’s Secret Chats have self-destructing messages, and many more. These features establish a time frame – from minutes to hours to weeks – before all the messages in your conversation are supposed to disappear from the devices of all participants in that conversation.

From a security point of view, it’s impossible to guarantee deletion in this way. Are these products all lying or deluded, then? No. These mechanisms are actually a great step forward for the public conversation — as long as users are aware of their limitations. Rather than provide some impossible perfection, what they do is to automate and normalize agreements about how long to keep records of your conversations with another person or people.

Why are these mechanisms inherently unreliable? Digital tools fundamentally work by making copies. You don’t actually “send” an instant message from one device to another, even though that’s how we talk about it. Rather, your device copies the message into the network and devices in the network make more copies of the message until a copy finally appears on the destination device. Modern instant messaging services encrypt the message before sending out copies, so the intermediate devices can’t see what is in the message. But the recipient’s device will decrypt the message so they can read it. This is called end-to-end encryption and it has become a fundamental part of today’s modern communication systems.

End-to-end encryption means that when you send a message, you don’t have to worry about anybody accessing the message between your device and your recipients’ –though your device itself could be vulnerable, which is a whole other cybersecurity issue. But, if you want to block the recipient from retaining a copy of the “disappearing” message, you’re out of luck. This is simply how the universe works: the sender of a message can’t actually control what happens when the recipient views their copy of the message.

To begin with, the recipient can always take a screenshot or make a backup of their app’s data. Also, even if the recipient’s device is somehow running completely locked-down software that prohibits screenshots and backups, the recipient can always point another camera at their screen when the disappearing message is displayed, or use another microphone to record a “disappearing” voice note. This is known as the “analog hole” — meaning that eventually digital data has to be translated into sights and sounds that we humans can perceive in the non-digital world and those sights and sounds can always be recorded.

It’s important to remember that if the disappearing messages feature was actually perfect, we might not actually be too happy. Imagine if someone could send you an abusive message and know that you could never show it to someone else who might be able to help to defend you.

Freedom, autonomy, and responsibility are good reasons why the recipient of any message should be in full control over their own endpoint, even if that means they might make a non-disappearing copy of an ostensibly disappearing message. In the case of an abusive disappearing message, and probably in other cases, the person “cheating” the system is actually in the right if they want to retain the message for non-nefarious reasons.

So even though disappearing messages can’t actually work reliably against someone determined to cheat the system, why are they still a great advance in public communications?

Before digital communications, messages were much less likely to stick around forever. There was often only a single copy of a message. In the past, a letter sent by the post office didn’t stay with the sender unless they deliberately made a copy first. In-person conversations also vanished as soon as they were spoken. As our society has digitized, however, more and more of our daily interactions leave a trail. Law enforcement agencies the world over seem to think that every human communication can and should now be permanently available to them whenever they’re interested. And old data left lying around on a device can also be misused by criminals, domestic abusers, or spies if they manage to get access to the device.

But if data is truly destroyed, it can’t be compromised, even if it was once available on your personal device, or the device of the person you were talking with. So one way to reduce the scope of this overreach is with a data retention/destruction policy, such as the disappearing messages feature. It’s possible to plan such a policy without a disappearing messages feature, for example, the people involved in a conversation could discuss and agree on when messages should be deleted, and check in with each other to ensure everyone involved remembers to go back and delete the old messages regularly. But negotiating such a policy among all participants in a chat can be difficult work. People chat to have a conversation about some specific topic, not about the conversation itself.

And even if you manage to get agreement from everyone in a chat on a data-destruction policy, getting people to follow through by actually deleting messages is a serious logistical challenge. The best time to delete a conversation is when it’s no longer important, and almost by definition at that point, the busy participants are usually already thinking about something else. But the disappearing messages feature delegates the task of following through to machinery that doesn’t get bored or distracted. This frees up human attention and energy to think about current problems and to not have to worry about older commitments.

A disappearing-messages feature in a messaging app serves two great purposes: 1) it normalizes and simplifies the act of agreeing on a data destruction policy; and 2) it helps honest participants keep their word. If all it did was help people negotiate an agreement on a data-destruction policy, that would be a win, but it wouldn’t be enough. Busy people need to find time to act on their agreements. Even the most well-meaning person can get distracted by other commitments and fail to follow up on what they had intended to do. But a tool with a disappearing-messages feature will follow through automatically, and the participants don’t need to think about it once the decision has been made.

These policies won’t stop someone who wants to break their promise about data deletion and sometimes it might even fail inadvertently. For example, someone might create a backup of their messages in a way that accidentally retains a message set for automatic deletion. But we know what it’s like when someone reneges on a commitment, or simply fails to follow through, and we have human ways of dealing with those scenarios.

These impossible, imperfect tools provide a healthy counterbalance to the disturbing trend of ever-increasing data retention. If you haven’t tried using them yet, now is a great time to start.

President-elect Donald Trump has nominated the Fox News Channel host Pete Hegseth to lead the Department of Defense (DOD). If confirmed, the military veteran will lead the nation’s armed forces in what will be his first appointment to a political office.

Hegseth was commissioned as an infantry officer in the Army National Guard and he served in Afghanistan and Iraq after 9/11. Prior to his stint as a talk show host on Fox News, he led the nonprofits Vets for Freedom and Concerned Veterans for America.

The ACLU has spent more than 100 years holding power accountable. While as a matter of policy the ACLU does not endorse or oppose nominees for cabinet-level positions, it does examine and publicize nominees’ civil liberties records. Given the power and influence defense officials have over U.S. national security policy and decision making, a president’s secretary of defense choice has serious consequences for civil liberties at home and abroad. Ahead of the January Senate confirmation hearings, we analyze Hegseth’s record on key civil liberties issues, and urge Congress to carefully consider the impact his leadership would have on our rights.

As the largest U.S. government agency with the largest discretionary budget, the DOD oversees all U.S. military operations. The secretary of defense is responsible for ensuring troops comply with all applicable laws, including the laws of war. Importantly, the secretary must comply with both the Constitution, which requires Congress alone to make the ultimate decision to go to war and use force except to repel a sudden attack (and then only for a limited period); and the War Powers Resolution, which Congress intended to reflect the Constitution’s checks and balances. The Constitution itself gives the power to declare war and authorize the use of force to Congress alone. The ACLU has long advocated against unlawful use of force abroad, as well as adherence to our system of checks and balances and international humanitarian and human rights law.

With blatant disregard for the appropriate role of the military on American soil, Trump has, on numerous occasions, stated that he plans to use military troops to help conduct his mass deportation plans, or suppress protest. Deployment of troops for these purposes would be an abuse of power. As secretary of defense, Hegseth could be called upon to support or carry out these extreme and unprecedented actions.

The DOD is the largest employer in the U.S., with nearly 1 million civilian employees and more than 2 million military personnel. Whether it’s protecting the rights of LGBTQ servicemembers and their families, ensuring that immigrant service members are given the expedited citizenship they may be entitled to, or demanding that parents be allowed to enroll and graduate from military service academies, it is vital for the DOD to protect the civil rights and liberties of its employees and comply with the rule of law in serving the American people writ large.

Hegseth has a long record of extremely concerning views on a variety of civil liberties issues related to the military and U.S. national security policy. His positions include:

1. He has excused war crimes. Disregarding the objections of senior defense officials, he encouraged Trump to pardon three U.S. servicemen accused, or convicted, of war crimes. Trump ultimately pardoned all three men.
2. He has supported overbroad claims of presidential authority to use lethal force without congressional authorization. He not only supported the Trump administration’s lethal strike against Qassem Soleimani, leader of Iran's Islamic Revolutionary Guard Corps-Qods Force, he also pushed for Trump to bomb cultural sites in Iran, which would have contravened the laws of war. Hegseth has also suggested that the U.S. use the military against Mexico’s drug cartels.
3. He has supported using the military to suppress protests. In 2020, he supported sending the military to U.S. cities, like Seattle, to suppress racial justice protests.
4. He has opposed efforts to fight discrimination in the military. Hegseth has stated that, “any general that was involved, general, admiral, whatever, that was involved in any of the DEI, woke s--t has got to go.” In reference to the current chairman of the Joint Chiefs of Staff, who is Black, Hegseth wrote, “Take it to the racist bank: black troops, at all levels, will be promoted simply based on their race. Some will be qualified; some will not be.”
5. He recently shifted his views on women serving in combat. In November, he said he opposed women in combat, and used gender stereotypes to make his case. He stated, “I’m straight up just saying we should not have women in combat roles. It hasn’t made us more effective. Hasn’t made us more lethal. Has made fighting more complicated.” But after meeting with several women senators in December, he said “we support all women in our military today, . . . combat included.”
6. Hegseth has also opposed medical care for transgender soldiers. He stated that transgender soldiers are “not deployable” because they are “reliant on chemicals” and referred to discussions on transgender issues in the military as “trans lunacy.”
7. He has made virulently anti-Muslim statements. He asserted that Muslim communities in America represent “an existential threat” to the country and repeated other vitriolic and hateful stereotypes about Muslims, who already face discrimination in the U.S., especially by national security agencies.

Finally, credible allegations exist that Hegseth has engaged in sexual misconduct, and the Senate must investigate the matter further before advancing his nomination. Given longstanding concerns regarding sexual assault in the military and the statements Hegseth has made regarding the role of women in combat, these allegations are directly relevant to his nomination as secretary of defense.

Based on his track record, the ACLU is concerned about how Hegseth would use the DOD’s vast power and resources, and about the impact his leadership would have on our civil liberties and civil rights. At his confirmation hearing, we’re urging senators to ask Hegseth:

1. When the framers drafted the Constitution, they wanted to ensure the clear separation of the civilian government from a nonpolitical, nonpartisan military. The military should have no role to play in mass deportation or suppression of protest and in fact we condemn other countries that send in troops to break up protests or enforce civil laws. Will you pledge not to deploy the military to intimidate or use force against protesters in American cities? Will you pledge not to deploy troops to carry out civilian law enforcement functions on American soil, which could place them at risk of violating criminal law?
2. In 2015, 78 Senators voted to ensure that this country never again engages in torture. Do you agree to support and adhere to that bipartisan pledge?
3. Adherence to the rule of law, including the laws of war, is critical for U.S. service members who rely on the secretary of defense to ensure they are not placed at risk of committing unlawful actions. Will you ensure that the DOD conforms to the checks and balances enshrined in the Constitution and act only as authorized by Congress, as well as international humanitarian law?
4. Will you support LGBTQ service members continuing to serve in the military, and also provide health care, including reproductive health care and gender-affirming care, for all eligible service members and their families?
5. In the space of less than two months, you went from arguing, ““I’m straight up just saying we should not have women in combat roles,” to later saying, “we support all women in our military today, . . . combat included.” Will you commit now to continue all of the Department’s current policies and practices that support women serving in combat and in combat positions?