Actually, I remember seeing a film about a similar thing - it was, apparently, 'based on a true story' - I can't remember the name of the film, but basically this book publisher gets sued for producing a book that is a 'guide' to how to become a good hitman. The book was used by someone who then became a hitman to carry out some nasty murders.
It was set in the US, so, naturally, the whole 'free speech' side of things initially blocked the publisher from being sued. However, the lawyers managed to convince everyone that the book
incited people to murder.
I wasn't entirely convinced by this, and it really is a very, very thorny issue in both legal and moral terms. Presumably Microsoft, with all their high-priced lawyers, have convinced courts that having such tools incite people to use them. It's also possible that somewhere in the EULA, that most people agree to without reading, it makes you agree not to use stuff like that or get in trouble! Patents may also be involved somehow, they normally are
I'm no expert and thinking out loud here, so feel free to correct me
hehe