Two weeks ago, conservative commentator David Harris Jr. took a video of himself posting to Facebook. Why video something so common? Because he had a hunch what would happen. Sure enough, his post went through, but a photo of a letter that accompanied the post mysteriously vanished and did not show up in his feed until days later - proof, he said, that the sharing service was biased against conservatives. At a Wednesday House committee meeting, Twitter CEO Jack Dorsey was barraged with examples from Republican congressmen of how conservative voices were being suppressed on its service. On the same day, the US Department of Justice announced that Attorney General Jeff Sessions would meet with state attorneys general to discuss concerns tech companies may be hurting competition and intentionally stifling the free exchange of ideas on their platforms." The immediate result is increasing and bipartisan pressure for social media platforms to be more transparent about their algorithms and how they block certain content. Longer-term, the threat is more regulation of the platforms, something that even free-market conservatives are reluctantly talking about doing if social media doesn't clean up its act. Twitter's Dorsey and Facebook's chief operating officer Sheryl Sandberg repeatedly denied that their companies were trying to tip the scales for or against any party or political ideology. But the pileup of anecdotal evidence clearly has exasperated conservative lawmakers.