He posts on Kohl. He knows this board is here, if he wanted to he could have post here too.
If you guys want to contact him, it needs to be done cleverly. If we hint we know him, he might get confused, or get spooked. He might bail, might investigate, might find it bullying.
We could ask him a couple of questions. Simple and innocent ones, which the admin would approve, and which might further confirm his identity. It has to be related to the topic on some level. For example we could confirm if that particular poster really is Swedish. Yeah, that "lobotomized nwo country" is a giveaway but maybe Swebernd and Idontuseacar are two people who read the idiom elsewhere, liked, and decided to use that themselves.