Blackboard is infamous for this. They hold patents for ridiculously vague definitions of web-based education...
It takes more space on their wikipedia entry than their actual products.
I wouldn't say 1 patent suit makes them overly-litigous.
The patent itself may be silly, and the beautiful part of the system is that it can be overturned. That happens very frequently.
This is just a case of eggs being broken to make an omelet.
"On March 25, 2008, the US patent office issued a non-final action rejecting all 44 claims of Blackboard's patent."
So what is all the fuss about?
In other words: the big guys don't have to win (their law suits) to win (wipe out or scare off the competition).