Snopes.com has become a byword for fact-checking rumors and urban legends, but it says it is now dealing with an all-too real crisis: a legal dispute.

Fact-checking website Snopes.com has launched an online fundraiser amid a legal battle with an outside vendor that Snopes says is holding it hostage and cutting it off from its source of revenue, raising the risk of closure.

Snopes started a GoFundMe campaign Monday to raise $500,000 for the site, with a suggested donation of $10. It says Proper Media cut it off from advertising income, will not return control of the site, is inserting its own ads on it and is withholding advertising revenue.

"Although we maintain editorial control (for now), the vendor will not relinquish the site's hosting to our control, so we cannot modify the site, develop it, or — most crucially — place advertising on it," the company said in a blog post on its site. "The vendor continues to insert their own ads and has been withholding the advertising revenue from us."

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A lawyer for Proper Media, Karl Kronenberger, tells The New York Times that Snopes founder David Mikkelson didn't properly cancel the contract and Mikkelson retains control of the Snopes.com domain name.

Snopes added, "Our legal team is fighting hard for us, but, having been cut off from all revenue, we are facing the prospect of having no financial means to continue operating the site and paying our staff (not to mention covering our legal fees) in the meanwhile."

Both sides have sued each other in California court.