Patent

Patents apply even in ignorance. So if you write a program, say a blackjack card game program, you will find out that you just violated a patent on computer card game programs. You will be sued even though you didn't know you violated a patent and defending the suit will cost you millions.

(IBM vs SUN story)

Patents have the potential to cause huge damage to the free software industry. You need to become aware of the patent threat. You need to become involved in fighting against software patents. You need to do this now. Europe is about to vote on software patent laws.