tiscali did a similar thing, except they advertised their service as unlimited (then is supersmall text buried deep inside the contract was something about fair use and what not) any way after 2 months of using it, the first 3 weeks of which where it wouldnt work at all because they some how forgot to turn the line on, (phoned up numerous times to be told the line was fine, then on the 5th call i actually told them go check the ****** thing properly....lo and behold the tech, indian with christian name like all of them, declares that actually the line wasnt ok at all) we get a letter telling us that we have been abusing the service and that we will be getting pushed into a "high usage" group (they lob all the high usage people onto a couple of dedicated exchanges so that "normal" users can use the internet properly) where our service will be less reliable and much slower, especially during peak hours.
i never even bothered ringin em back up, ******. i dunno how they got to that conclusion, me and all my house mates were usually out of the house alot of the time, and the router we had at the time would flake out 2-3 times a day (on the days i was in, i had to reset the router that many times) so torrenting etc was jus pointless.