A week ago Russian authorities have detained a university teacher, Free software programmer and activist Dmitry Bogatov (http://sinsekvu.github.io/pages/about.html). He was charged with incitement to "extremist activities" and linked to anonymous posts on the Internet about one suspiciously provocative antigovernment protest on April, 2. Moscow court declined to put Bogatov under arrest, so the Investigative Commitee doubled down on the case and charged him with incitement to "terrorist activities" and "preparing to organize civil unrest" overnight. He was subsuquently arrested on April, 10 (https://zona.media/online/2017/10/04/bogatov-3#12002, Russian language link).
Dmitry Bogatov says he did not post anything about this mysterious protest that had no organizers and was attened by few people. He does however appear to have been maintaining a Tor exit node from his home (https://atlas.torproject.org/#details/2402CD5A0D848D1DCA61EB708CC1FBD4364AB8AE). It is therefore possible that the author of those posts "inciting to extremism/terrorism" just got Bogatov's IP-address on a random basis: his account continues posting from various IPs.
Couldn't find any English-language articles about his case so tried to describe it the best possible.
(I am a Russian journalist; it's late in Moscow, so replies can be slow)
Tor user and GNU activist arrested in Russia over “incitement to terrorism” | Heykuki News