Don't you think you're overreacting? Distributed computing isn't dangerous for you at all. It usually doesn't consume cpu time when you need it and it also doesn't harm your privacy. All you'd do is lend your cpu to do a couple of harmless calculations from time to time, when you wouldn't even notice it.

If you think the grid computing part about kazaa was dangerous you have absolutely no clue, since it's not. The only real problem about Brilliant Digital's Altnet is its auto-update. For who's going to make sure some hacker doesn't use it to infect you with a virus? Auto-updates in a p2p network are insecure by definition.