I’ve torrented a few videos from them a while back. Haven’t had any issues so far. Usually when I’m weary about viruses, I’d use a virtual machine and run a virus scan on there. Although in the case of porn, I usually don’t bother because I don’t expect video files to be laced with viruses (not to say that it can’t happen, but virus-laced videos are pretty rare).
Now if you’re downloading porn games, that’s a different story. Executable files are usually where you get all the viruses and stuff, in which case, I’d say you should be weary around those.
I do recall that they had a rule where you have to contribute by seeding files, otherwise they’d ban you. They keep track of how many megabytes you’ve downloaded and seeded and it’s displayed on your profile. I think they require a minimum 3:1 download/upload ratio or something like that (it should be in the rules somewhere).