Actually, this happened to me back in March - I logged in one evening to LJ to find my journal had been suspended. I reported it immediately and I was back by the next morning. The explanation I got just said that my journal had been flagged as a potential source of spam - it didn't gave any details as to why it had been flagged.

But I think this spambot script must be the explanation - I use an awful lot of links in modposts. However, it must be said I've continued to link with abandon in comms and in my own journal since March and I'm still there on LJ. It all did give me and my co-mod the push to start backing everything up on DW though.