How to bog down a network?

I'm trying to win an argument about my currently crappy internet. Right now it maxes at 100KB/s. This is not because of poor service or internet hogging or anything like that. It's because it's an 8 year old paid service from Earthlink where I'm pretty sure we managed to grandfather ourselves into the most backwards unusable internet.

_

The main argument I'm fighting against right now is "it works just fine for me". So, since very expensive dial-up is more than sufficient for them (but not for anyone else in the house), I'm interested in how to bog this internet down long enough for them to cave.

For science, of course.