Some bloggers opposed to Barack Obama say they suspect Obama's supporters — with the assistance of Google — may have tried to censor them when the Internet giant froze their Web sites for five days last month.

Seven blogs run by Democrats who oppose Obama’s nomination for the presidency were incorrectly flagged as spam sites by Blogger, the hosting service Google has owned since 2003. Google says it was an automated response from a spam filter.

But the bloggers believe that Web surfers who support Obama took advantage of a loophole in Blogger’s system that allows readers to report spam blogs, the artificial Web sites that abound on the Internet and are used to promote other sites.

"It appears that [Blogger's] policy can be manipulated by people determined to shut down the free exchange of ideas," said Carissa Snedeker, whose blog, BlueLyon, was among those that were frozen.

"It’s unusual — I’ve never heard of similar blogs of the same nature being shut down like that," said Danny Sullivan, editor-in-chief of the tech site SearchEngineLand.com.

Google said in a press release that the blogs were blocked because an automatic spam filter had locked on to those seven Web sites.

"We believe this may have been caused by mass spam e-mails mentioning the ‘Just Say No Deal’ network of [anti-Obama] blogs, which in turn caused our system to classify the blog addresses mentioned in the e-mails as spam," Google wrote, referring to a coalition of disaffected Democrats who oppose Obama's candidacy.

Blogger quarantined the seven anti-Obama blogs on June 25 while it conducted a review, a process that took five days and made it impossible for the bloggers to write posts on the weekend of a joint event held by Obama and Hillary Clinton.

"Blogger’s 'guilty until proven innocent' approach is appalling," wrote blogger GeekLove on her site, Come a Long Way. She said she felt silenced by the freeze.

"The conclusion that many of us came to was that we were specifically targeted by some over-enthusiastic Obama supporters," Snedeker said.

The bloggers believe it's part of a larger campaign to evict them from left-wing sites like the Huffington Post and DailyKos.

Google says the bloggers' suspicions are unfounded. "Politics had absolutely nothing to do with this — it was a spam issue," Google spokesman Adam Kovacevich told FOXNews.com.

Sullivan said he would have expected more blogs to get shut down if there had been a concerted effort to stop anti-Obama sites.

"I think that there’s something weird, in general, that all these were shut down," he said, "but why, exactly, is uncertain."

As a result, all seven bloggers opened accounts with WordPress, a rival blog-hosting site, hoping to avoid such problems. The other affected blogs are Hillary or Bust, McCain Democrats, NObama Blog, The Political Lizard and Reflections in Tyme.

Google said it was addressing the issue and "constantly evaluating our policies and technology to reduce the number of false positives caught by our spam filters."

"We have restored posting rights to the affected blogs," it wrote, "and it is very important to us that Blogger remain a tool for political debate and free expression."

Snedeker wrote on her blog that she wasn’t satisfied with Google's gesture.

"How’s about a little benefit of the doubt for the next set of bloggers that get caught in your 'automated spam detection' maze?" she wrote.