Facebook is being accused of fiddling with its formulas to suppress conservative news.

That’s what some unnamed former Facebook contractors told the tech site Gizmodo—and it’s an accusation that strikes at the heart of the social network’s credibility.

Facebook relies on computer algorithms to determine what is “trending,” an influential designation that inevitably boosts traffic for what are deemed the hottest topics. But unbeknownst to much of the public, Facebook hires journalists to tweak these formulas, and this is where the question of political bias has erupted.

Is Facebook, one of the world's most powerful distributors of news on the Internet, censoring politically conservative articles?

Facebook denies it, but that's the allegation in a published report that set off a firestorm among conservative media on Monday.

The great irony of the tech blog Gizmodo's revelation that Facebook's trending-topic curators weeded out stories about Facebook or about issues popular with conservatives is that Gizmodo's story therefore likely won't end up on Facebook's list of trending topics. After all, the report, which suggests that the social media behemoth's team filtered out stories on conservative topics from conservative sites, will most certainly be very, very popular with conservatives. (Update: Or maybe it will.)