If we can set aside the moral quibbles over P2P for a moment - 
I have just been migrated to Vodafone's Red Network, and I must say, I've never experienced such poor torrent speeds. Even though my linerates are ~10mb/1mb, I'm only getting ~20kb/s download speeds, and yes, these are popular torrents with plenty of seeders. What gives? Even on my old regular ADSL plan, I was consistently hitting 100kb/s+.
What's really odd, is that when I first initiate the torrent download, it spikes up to around 500-800kb/s for like, 10 seconds, and then it's almost like the network registers it's P2P traffic and drops it down to those aforementioned appalling speeds.
Any ideas/help/explanations?