My ISP, Virgin Media, advertises “Size L, Up to 4Mb, No Download Limits† (unlike some of our competitors)” where the † is a link to the Acceptable Usage Policy (the other grades of service are similar).
Now some people have said that this is a cap in disguise, but I have read all the small print, and it is small, and it makes no mention of any limit of usage except in sections about operating servers (section 7.3 w.r.t. upstream traffic), incoming email (section 9.2.7) and webspace traffic (section 10.6). So if they do have a capping system then it would be in contravention of their own AUP. If they are relying on section 3.2, which talks about “using…to the detriment of other Internet users” then I would think they were on very weak ground.
The only other possible clause is not in the AUP but in the Terms and Conditions section B.4.i where it talks about “usage allowance applicable to your Internet access” but nowhere does it define what this is.
Indeed the AUP is much less restrictive than I remembered or expected. I thought running servers was banned altogether. The only awkward and loose clauses I can see are 6.1.2 banning advertising and 6.1.4 banning business use which should worry big eBay traders.
P.S. Which? has recently criticised the “Up to” phrase but I am getting 3.7Mb and am not at all unhappy with it.