They used the One-Click patent against their then biggest rival Barnes & Noble

http://en.wikipedia.org/wiki/1-Click

Several organizations have boycotted Amazon for that:

http://www.gnu.org/philosophy/amazon.html

Thats pretty low, but only reinforces the notions that IP is bad for consumers.

1-Click purchases, which is close in ridiculousness. Buying stuff online clicking once was such an outstanding innovation that it surely deserved protection from all those thieves who never could have figured that out by themselves...