The University of Denver (DU) maintains a “free speech wall” for students to use to express themselves in paint—a common feature on college campuses, often taken the form of a wall or a rock. But now, after someone used the wall to paint lyrics from a punk rock song (Minor Threat’s “Guilty of Being White”) and altered a “Black Lives Matter” message, DU has placed restrictions on what the wall may be used for.

And they’ve added a camera:

Students or organizations are encouraged to identify themselves in the message. We expect our community to stand behind their words and art; anonymity does not allow for dialogue and allows one to disrupt community standards without facing the impact and accountability of their work. A camera has been put in place to monitor The Wall, and students in violation of the above guidelines will be subject to a student conduct evaluation facilitated by the University administration. The Wall is a vehicle for expression, for inquiry and for inclusivity. These guidelines are not intended to restrict free expression; rather they are a means through which we can continue to thrive as an inclusive community with a shared value system and many varied viewpoints.

That DU casts its surveillance and condemnation of anonymous speech as if it is in service of open dialogue is an embarrassment. But it’s not surprising: Efforts to construct mechanisms to monitor and punish offensive speech will often be accompanied by purported paeans to the value of freedom of speech.

Free speech walls serve more than a promotional function (i.e., they exist for more than the purpose of organizations promoting an event). They’re an easy outlet for people to share messages quickly and, often, anonymously. Students who used the wall to speak their minds may not have access to resources that would allow them to quickly and cheaply share their message otherwise, save for social media. Those messages may offend others, and sometimes that’s the point.

By providing a canvas for students to share messages cheaply and anonymously, DU helps students share their thoughts. But it also did itself a favor, providing a space where students have a creative outlet, when they might otherwise create a canvas of their own on other walls—walls DU doesn’t want students to paint. In restricting what may be painted on this wall, DU will create a perverse incentive: if you want to paint a message that may offend others (or campus police who might not be impressed by, for example, a message condemning police brutality), find a wall without a camera pointed at it, so that you don’t get caught.

Last month, another university’s president—Mark Schlissel of the University of Michigan —warned that pursuing surveillance of its students in the service of deterring offensive speech would be akin to instituting a “police state”:

I have absolutely no idea to how to prevent one person with hate in their heart from posting a poster in a building of a public university. Don’t know how to do that. I’ve never heard a good idea about how to do it. We’re not going to turn the University of Michigan into a police state where there are people and cameras everywhere you look and you’ll never have a private moment. Because that’s what it would take to prevent hateful posters by one sick and mean and terrible person to hurt all of us.

That observation is apt. Combatting offensive speech is not accomplished by erecting cameras and rules—tools which will always be used by those in power to discourage or punish those who are not. Instead, it’s accomplished through education, and through more speech. By closing students’ avenues to speech under the guise of protecting it, DU does itself and its students a disservice.