The report on ADSLGuide suggests that these 0.3% of users causing the problems (not that I see any problems) are using an average of...
140Gb per month!!
People can argue whatever they like about capped and uncapped, but 140Gb is excessive!
I've got no problem with them limiting these users. If those 0.3% really want that level of movie pirating they may as well buy a dedicated line for all the profits they probably make