I have had a search of this but couldn't find anything so sorry if it's been discussed before and I've missed it.

What is your stance on a poster searching someone's posting history and bringing it up on another thread in an accusatory way or to attack that poster?

completely random and probably feeble e.g "Ah I see you say you bought a budgie and now you've gone and got a cat, that poor budgie I think that's disgusting and cruel"

Is it merely frowned upon, or if one finds it offensive what should one do?

TIA