According to British CacheLogic, the global cost of P2P networks for ISPs will top £828M (€1148M, $1356M) this year and will triple in 2004. Various ISPs have considered of taking measures for restricting users' download habits, but a prime example from the UK, by cableco ntl, has shown that it might not be a very smart move (ntl imposed a 1GB/day limit for its cablemodem connections and thousands of users left the service immediately, taking also their digital cable TV accounts to competitors as well). Now some tech companies are trying to invent ways to prioritize the traffic -- if the file-trading is done within the ISP's network, the cost for the ISP is minimal compared to intercontinental network connection costs.
Source: ZDNet UK