Tor has published what it calls a "Social Contract" comprised of promises to users and the principles the team believes in. It has been around for over a decade, so publishing a set of goals and behaviors at this point in time is rather curious. Maybe its developers wanted to show the world that they didn't lose their focus after Jacob Appelbaum, one of Tor's most prominent devs, stepped down in the midst of sexual harassment allegations. Maybe it's because of something else. Whatever the reason is, its social contract contains one interesting pledge: "We will never implement front doors or back doors into our projects," the team wrote.
Tor's ability to keep users anonymous made it the go-to browser of people looking for drugs, illegal firearms, hitmen, child porn and other things you won't find on eBay or YouTube. If there's a browser law enforcement agencies would want to backdoor to, it's Tor, especially since its main source of funding is the US government. That's right -- the famous anonymizing network gets most of its money from a government known for conducting mass surveillance on a global scale.
Loudly proclaiming that it will never build a backdoor into its services might not even matter, though. The government already proved once that it's capable of infiltrating the dark web. If you'll recall, the FBI identified 1,500 users of a child porn website called "Playpen" by deploying a Tor hacking tool. It led to numerous court battles that opened up the discussion on the validity of evidence obtained without warrant through malware.