If you were trying to share something on Facebook today and couldn't, you weren't alone.
Facebook's security systems were blocking a number of high-profile websites from sharing content from third-party sites to the social network.
The social networking giant confirmed that one of the site's spam filter -- specifically used to prevent the spread of malware -- encountered an issue, a spokesperson said.
We tried to share a number of articles to the social network from share buttons on popular news sites -- including Reuters, Bloomberg, The Wall Street Journal, and Ars Technica -- but they were all met with the same message from Facebook saying the content couldn't shared.
ZDNet, too, at the time contained "content that has been blocked by our security systems," according to a message received when posting content.
Facebook says in its help guide that a block can last "a few hours or a few days." The guide also says that the company "can't lift this block for any reason."
Posting directly to your timeline or page on Facebook.com works fine, however, suggesting it's an issue with the site's sharing plugin for third-party developers and sites.
The issue appeared to begin early Monday morning in New York, but an exact time isn't known. According to Facebook, all systems were running fine at the time of publication.
What's likely an overzealous spam filter could have severe repercussions for websites that depend on Facebook for traffic, at a time when the company has already faced controversy for its role in alleged censorship and in steering readers to false news.
Updated at 12:20pm: with news that the issue had been resolved, and added comment from Facebook.