If you have Comcast High-Speed Internet, don’t download more than 600 gigabytes within a month or you could find yourself Comcast No-Speed Internet. I saw this  on Digg and never knew there was a shroud of mystery surrounding an invisible bandwidth limit and getting booted but apparently it’s floating out there. An anecdote  shows that 600 GB appears to be the limit at which Comcast company policy states considers your usage to be ‘internet abuse.’
600 GB/month = 20 GB/day = 833MB/hr. Eight hundred and thirty three megabytes downloaded an hour, each hour, for thirty consecutive days… even I would consider that abuse.