Verizon has its customers' backs.

The Internet service provider is refusing to give up the personal information of customers that book publisher John Wiley & Sons allege are online pirates -- despite the threat of subpoena. Verizon has instead called into question whether the information would lead to any relevant findings and expressed concerns about the violation of privacy, according to TorrentFreak.

Verizon's unwillingness to give up the information is significant because its challenge could signal a potential hurdle for content companies looking to prosecute individuals using Bittorrent to illegally download books, movies, and music.

A key argument is whether the actions of IP address can be directly linked to a specific person. Verizon doesn't appear to believe so.

Verizon also asserts that its customers' information is protected from disclosure by the right of privacy and protection guaranteed by the first amendment, and lists several other objections. In addition, the company is worried Wiley & Sons is using the personal information to harass, delay, or increase the cost of litigation."

Unlike Verizon, most of the other ISPs have complied with the subpoenas issued to them by Wiley & Sons.

Verizon declined to say little more, adding only that, "our objections are of a technical nature."

Updated at 12:33 p.m. PT: to include a response from Verizon.