On Tuesday, Facebook released a new tool that shows who's spending the most money on political ads on the platform in the US. At a glance, the Ad Archive Report suggests that Texas senate candidate Beto O'Rourke is the biggest spender, having plowed more than $5 million into Facebook ads since May. But the fine print reveals a more surprising finding: The advertiser spending the most on political and issue ads on Facebook is, well, Facebook.