Popular torrent hub The Pirate Bay suffered an extended outage on Monday and Tuesday, coinciding with a government raid on its former Web hosting service. The site says it's down mainly because of a power outage, however, and that it will be back later this week.

Users of the infamous digital piracy site began flooding The Pirate Bay's Facebook page early on Monday, complaining that the Sweden-based site wasn't working. Prolonged outages often spook Pirate Bay fans, since the site is firmly in government crosshairs around the world.

It's the most famous nexus of illegal downloads and the embodiment of what anti-infringement legislation like SOPA aims to kill. On a typical day, several million users swap files through the site's links. When Pirate Bay goes down, a significant chunk of the Internet's piracy infrastructure goes down with it.

Swedish law enforcement agents on Monday raided PRQ, a web host started by two Pirate Bay co-founders, according to reports in TorrentFreak and other news outlets. The raid knocked PRQ and many of the sites it hosts offline, fueling speculation that Pirate Bay was a target of the crackdown.

PRQ's clients include WikiLeaks and a number of controversial blogs. Pirate Bay's operators claim that they are minimally affected by the PRQ outage, though.

"We have a relay there but not that much more," the Pirate Bay's operators wrote on their Facebook page. "This combined with a power failure at another place is the reason why we're down at the moment."

The Pirate Bay page said Monday that the site would soon "be back with full force, hopefully later today," but on Tuesday, that target was pushed back.

"Looks like we won't be up until tomorrow," The Pirate Bay posted on Facebook around 2:30 p.m. ET on Tuesday.

The Pirate Bay has survived forces much stronger than power outages during its nine-year existence.

Swedish anti-copyright organization Piratbyrån started The Pirate Bay in late 2003, taking advantage of the country's lax copyright laws. By October 2004, a handful of individuals were running the site independently.

Operated by an organization registered in the Seychelles, The Pirate Bay bills itself as the "world's largest tracker of BitTorrent files."

BitTorrent is a free, peer-to-peer software program that lets users swap and download large media files. The tool has many legitimate uses, but it's also heavily used to illegally trade movies and other copyrighted content. The Pirate Bay simply operates a torrent tracking network, linking together users who connect directly to make their trades.

No copyright-protected files ever sit on the site's own servers. That makes it very hard to kill.

The site has been targeted by governments around the world, and U.S. Senator Orrin Hatch, who co-chairs the Congressional International Anti-Piracy Caucus, once denounced it on the Senate floor. Last December, the Office of the U.S. Trade Representative highlighted The Pirate Bay on its list of "markets notorious for piracy."

The site has weathered police raids before, including one in 2006 that closed the site down for three days after its servers were confiscated. To evade shutdown, it has occasionally changed Web hosts and domain names.

In 2007, Swedish officials charged three Pirate Bay operators and one of its financiers with "promoting other people's infringements of copyright laws." The trial took two years and ended with the conviction of operators Fredrik Neij, Peter Sunde and Gottfrid Svartholm as well as businessman Carl Lundström.

The four were sentenced to one year in jail and a fine of $905,000 each. All except Svartholm, who was ill and skipped his scheduled court appearances, appealed the sentence, and in 2010 it was amended to include less jail time but a higher fine.

Svartholm disappeared for several years, but last month, he was arrested in Cambodia in connection with the alleged 2010 hacking of a Swedish IT company. He was deported back to Sweden, where he is now in detention awaiting formal charges.