Same. I've really only heard about it in the media, especially referenced as 'an app where some videos get posted' - and I'd assume there is a private message feature...
Don't know much else about it.
I know the CEO has been a huge proponent of free speech, and has resisted the attempts of various governments to censor his platform. But there is a big difference in being a proponent of free speech and refusing to censor content, and turning a blind eye to blatant criminality of the worst kind...and I suspect it's the latter they are using as the context for his arrest.
But this guy isn't stupid, not by a long shot. I'm with Bri on this, I think it's something to watch also...