CHICAGO (WBBM/AP) - An Internet detective is explaining how Pakistan's effort to block domestic access to YouTube on Sunday, managed to make the site disappear in many countries for about two hours that evening.

WBBM’s John Cody reports.

Separately, Pakistan's telecommunications regulator said Tuesday it had lifted restrictions on YouTube that knocked out access to the video-sharing Web site.

The Pakistan Telecommunication Authority told Internet service providers to restore access to the site after the removal of what it called a "blasphemous" video clip, featuring a Dutch lawmaker who has said he planned to release a movie portraying Islam as fascist and prone to inciting violence against women and homosexuals.

The authority aimed to restrict the site only in Pakistan, but the move inadvertently cut access for many of the world's Internet users for up to two hours on Sunday.

Todd Underwood is vice-president of Renesys, a Manchester, N.H.-based company that tracks Internet pathways for telecommunications companies.

He says what Pakistan's government did was to pose as YouTube, diverting Pakistani traffic to Youtube down, in effect, a black hole to nowhere.

Underwood said another major Internet data carrier picked up the false address so almost all YouTube requests were diverted down that same black hole in Pakistani cyberspace.

Underwood said Pakistan wasn't trying to bring down YouTube, just ensure its own citizens couldn't get there.

Underwood said this shows the fragility of the Internet which is largely unregulated. He said it's this open architecture which allows it to flourish while at the same time allowing such shenanigans.

He said participants in the Internet are studying how they might control such interference.