Last Thursday, the Justice Department announced that it had worked with European authorities to shutter two of the largest destinations on the dark web to buy and sell illegal drugs, AlphaBay and Hansa.

The shutdown followed reports from earlier in the month that AlphaBay, the larger of the two, had mysteriously stopped working, causing users to flock to Hansa. But it turns out that Hansa had been taken over by the Dutch national police, who were collecting information on people using the site to traffic drugs.

European and American law enforcement collaborated to quietly arrest AlphaBay’s alleged founder Alexandre Cazes in Thailand on July 5. The 25-year-old Cazes later committed suicide in a Thai jail, according to the New York Times.

These dark web drug marketplaces are accessed using a service called Tor, which allows users to browse the internet anonymously. With Tor, you can circumvent law enforcement surveillance as well as internet censorship filters, which are often installed by governments or companies to restrict where people go online. Tor also allows for the creation of anonymously hosted websites or servers that can only be accessed via the Tor Browser. AlphaBay and Hansa were both hosted anonymously on Tor.

Though AlphaBay, Hansa, and, most famously, Silk Road depended on Tor to run their illegal operations, the Tor Project, the nonprofit that maintains the anonymous browser and hosting service, says that only 2 percent of Tor traffic has to do with anonymously hosted websites. The vast majority of Tor traffic is used for browsing the web anonymously. More than 1.5 million people use Tor every day, according to a spokesperson.

The U.S. government has a rather complicated relationship with Tor. On the one hand, documents revealed by Edward Snowden revealed how the National Security Agency had been trying to break Tor for years, searching for security vulnerabilities in browsers that would allow law enforcement to crack the online anonymity service. The Department of Defense has also invested in trying to crack Tor. During the 2016 trial of one of the administrators of Silk Road 2.0, another shuttered dark web drug-trafficking site, it was revealed that DoD hired researchers from Carnegie Mellon University to try to break Tor’s encryption in 2014.

Yet Tor also wouldn’t exist without the U.S. government—it was originally built as a project out of the U.S. Naval Research Laboratory. The State Department continues to fund Tor (at least someone has told Rex Tillerson about it, presumably) because internet users around the world rely on the anonymity tool to access information and communicate safely online, particularly in countries where the internet is heavily monitored or censored by the government, like in China with its national firewall, or in Thailand, where it’s illegal to criticize the royal family online.

Cazes, the AlphaBay ring leader, was caught thanks to investigative work, not a break in Tor’s encryption. Cazes had sent password recovery emails to his email address, which investigators used to find his LinkedIn profile and other identifiers. (And no, the FBI did not dig up an email from Cazes asking to join his professional network on LinkedIn. According to The Verge, Cazes used the same address on a French technology troubleshooting website, which listed his full name, leading investigators to find a LinkedIn profile where he boasted cryptography and web hosting skills, as well as involvement in a drug front.)

And that’s good news for the vast majority of Tor users who aren’t interested in scoring molly. In 2015, a report from the U.N. declared that anonymity tools “provide the privacy and security necessary for the exercise of the right to freedom of opinion and expression in the digital age.”

Anonymity tools, like so many technologies, have both good and bad applications. And in the same way cellphones aren’t evil just because some people use them to make drug deals, it’s important to not malign anonymity tools just because some people use them to sell drugs, too. If the U.S. government is ever successful in finding a way to disable Tor’s encryption to find criminals, it could put hundreds of thousands of people who depend on Tor at risk, too.