I think red tag here is uncalled for. Expressing an opinion (no matter how wrong or "FUD" it may seem to someone else) shouldn't make a user "high risk".

Frankly (some minor pun intended) I would even hesitate to call franky1 a troll, he doesn't appear to be winding people up on purpose or at least that's not his primary purpose, it just happens as a result of his very headstrong opinions.

Having said that, if he breaks the rules - report him by all means, but that's unlikely to result in a ban. He's not plagiarising or evading a ban or moving a thread somewhere. The real solution here would be to put him on ignore, or if you care enough - create a solid rebuttal thread with all the LN stuff etc and respond with a link to that thread when he derails a discussion, thus negating his potential negative impact on newbies etc.