From the points made in this article:
http://www.hightech-iplaw.com/leswibar2003.pdf
I have some numbers for you....
76% of all patent infringement suits settle without trial
Average of $1 million in legal fees & court costs after going through discovery
Defending against a claim of patent ingringement is gonna run you about $1.5 million.
Oh ya, if you do end up going to trial and you lose - you can be assested penalties and all of the legal fees for both sides. Of course if they lose, they pay your legal fees.
They are banking on the fact that many will not be able to afford this and just pay the licensing fees. It is often times a lot cheaper for people to settle and buy the license than it is for people to fight it.
Flow