Allegations that Facebook censored conservative news and media outlets from appearing in a section the site devotes to “trending news” sparked uproar among right-leaning groups this month. However, some observers contend, the site has a storied history of discriminating against conservatives, and the revelation about censorship should not have come as a surprise.

“We have had posts about materials contrary to Facebook’s political agenda completely disappear from our main page no matter how many times we post the message,” said William Gheen, the founder and president of the Americans for Legal Immigration PAC, a conservative group advocating for legal immigration. “I have almost exclusive control over these pages, so we know nobody on our team was responsible for the deletions.”