I know we haven't published the guidelines yet but publicly referring to someone as a troll either directly or indirectly will not be acceptable on these forums. Suggesting someone may be a troll because of their ideas rather easily falls into the 'pejorative characterization' category. Viewpoints should stand or fall based on the weight of evidence one brings to the table not on who's delivering the evidence.
If you feel that someone has 'invaded' the forums then please contact one of us privately but the idea of invasion itself is rather foreign to the concept of a forum. What we are chiefly worried about are people whose behavior - not their ideas - are disruptive to the free exchange of ideas.
But Alice did not call someone a troll, she spoke of a troll on another group that ended up with a police caution which is a serious matter and not something the police would do on spurious evidence. I don't see how Alice has been perjorative towards anyone. I don't mean to cause a fuss, but I found this post quite harsh for everyone to read publically. If suspicions should be dealt with via PM perhaps posts like this should be too.
Looking forward to some proper guidelines up soon then we'll know where the ground lies.