Suing tens of thousands of accused peer-to-peer movie file-swappers—it can be a lucrative business model, but it works well only when Internet service providers can turn huge lists of IP addresses into real names and addresses in a timely fashion. But what if a major ISP like Time Warner Cable only had to do 28 of these lookups a month? And might take three years to burn through its entire list?

Time Warner Cable has pleaded with the federal judge overseeing several of the P2P cases brought this year by the US Copyright Group. The company averages 567 IP lookup requests per month, nearly all of them coming from law enforcement. These lookup requests involve everything from suicide threats to child abduction to terrorist activity, and the company says that such cases take "immediate priority." It says that, without a major staffing increase, it simply cannot turn around more than 1,000 requests in a timely fashion without compromising the much more important requests from law enforcement.

TWC requested that the judge limit subpoena lookups for the US Copyright Group to 28 per month. In response, lawyer Tom Dunlap blasted TWC as a "good ISP for copyright infringers." He went on to threaten the company, saying, "To the extent TWC’s tactics are just that—letting the public know that TWC is a good ISP for copyright infringers because TWC will fight any subpoenas related to infringers’ activities—TWC exposes itself to a claim for contributory copyright infringement."

Judge Rosemary Collyer, who is overseeing the Far Cry and The Steam Experiment cases, doesn't agree. In a recent ruling, she has modified TWC's subpoenas so that the company "shall provide identifying information for a minimum of 28 IP addresses per month." And that's not 28 per month, per case; it's 28 per month total for both cases combined.

How long will it take to get through all these subpoenas? Several months ago, TWC faced 809 lookup requests related to the Far Cry case alone. Since that time, the plaintiffs have added several thousand more IP addresses to the case, and more requests have come from the Steam Experiment case.

Assuming a lowball estimate of 1,000 IP addresses that belong to TWC, the company may take nearly three years to do all of its lookups.

Collyer's ruling doesn't affect the other P2P cases brought by US Copyright Group that are being heard by other judges, and it doesn't affect other ISPs (TWC was the only one to object so strongly). But it does suggest that federal judges are sympathetic to the argument that law firms can't simply dump thousands upon thousands of IP addresses on ISPs and demand quick responses.

In addition, Judge Collyer refused to "sever" the thousands of defendants in each case, as requested by the EFF and ACLU. "But they may be severed in the future," she wrote.