There's groups sponsored by software companies to stop illegal swapping of software. They do it by spamming viruses. Here's an example of such groups (a) Overpeers, (b) MediaSentry, (c) Mediadefender
I would classify them as terrorists. Most countries including in the USA have laws against the deliberate spreading of viruses.
So really the likes of RIAA, MPIA, softw cartels, etc. are a bunch of hypocrites!