I've discussed the PIRATE Act here (PIRATE Act Reveals Sen. Hatch as Strange Ally of Pornography Industry), which Copyfight has followed up here (Larry Flynt, Poster-Child for the PIRATE Act). However, having thought about the proposed law a little more, I came to an interesting realization: you can get wiretaps for federal copyright infringement investigations.
Under 18 USC 2516(3), you can get a wiretap for any "electronic communication" (but not for wire or oral communications) as long as "the interception may provide or has provided evidence of any Federal felony." Copyright infringement under 17 USC 506 is a felony. Under the proposed PIRATE Act, the government has options with regard to people who violation 17 USC 506 (Criminal copyright infringement). The government can criminally prosecute them or bring a civil suit. Either way, the government can use a wiretap to gather evidence for their case.
Under a regular civil suit for copyright infringement by means of file sharing, the copyright holder can only observe that the infringing files are available for download. They can't really tell how many people have downloaded them, if any. Furthermore, copyright holders have no way of going after people who are only downloading files and not uploading them. Wiretaps to the rescue. The RIAA may not be permitted to wiretap file sharers, but the government certainly can. The RIAA must be salivating at the prospect.