After being challenged by Grande Communications, piracy monitoring outfit Rightscorp has withdrawn its request to identify the hundreds or thousands of customers who it earlier accused of piracy. The ISP is not letting Rightscorp walk away that easily though, and has asked the court for sanctions.

For several months Rightscorp has been sending DMCA subpoenas to smaller local ISPs in the United States.

Unlike regular subpoenas, these are not reviewed by a judge and only require a signature from the Court clerk. This practice raised questions because DMCA subpoenas are not applicable to file-sharing cases, which is something courts determined more than a decade ago.

Perhaps unaware of the legal precedent, most ISPs have complied with the requests. Until last week, when small Texas provider Grande Communications stood up in court after it was asked to reveal the account details connected to 30,000 IP-addresses/timestamp combinations.

Soon after Grande filed its objections Rightscorp decided to drop the request entirely. While ISP is pleased that its customers no longer have to be exposed, the company is not letting Rightscorp off the hook.

In an advisory to the court (pdf) the ISP notes that Rightscorp’s actions suggest that it’s merely trying to avoid having a judge look at their dubious efforts.

“The abrupt withdrawal of the Subpoena is consistent with the apparent desire of Rightscorp and its counsel to avoid judicial review of their serial misuse of the subpoena power of the federal courts,” Grande’s attorneys write.

The ISP still wants Rightscorp to pay for the costs run up thus far. In addition, Grande also believes that sanctions for misusing the federal court’s subpoena powers may be in order.

“The U.S. District Court for the Central District of California may consider ordering Rightscorp and its counsel to show cause why they should not be sanctioned for misusing the federal court’s subpoena powers,” the advisory reads.

The ISP points out that if it hadn’t challenged the subpoena, the personal details of hundreds or thousands of subscribers would have been shared based on a faulty procedure. Since similar requests are being sent to other ISPs, the matter warrants further investigation.

“It appears clear that Rightscorp and its counsel are playing a game without regard for the rules, and they are playing that game in a manner calculated to avoid judicial review. Hopefully, they will not be permitted to continue much longer,” Grande’s attorneys conclude.

Rightscorp’s withdrawal of the subpoena also contradicts earlier comments the company’s CEO Christopher Sabec made to TorrentFreak.

Sabec told us that the company believes that earlier decisions on the legitimacy of DMCA subpoenas in file-sharing cases were wrong, and will be overturned should the issue reach the Supreme Court.

Apparently, this was a veiled threat, perhaps to discourage Internet providers from starting a battle that could get very expensive. Instead, with possible sanctions pending, things may now get expensive for Rightscorp.