U.S. Senator Michael Bennet, like most politicos, is on Facebook, where he “friends” people and posts photos. He occasionally highlights his latest bloggery, including, it turns out, a rant against Facebook. He’s not upset enough to quit Facebook, but like many on the social-networking site, he’s kind of concerned about the possibility that content people expect to be semi-private can now be shared with third-party websites—unless users go through a rigorous opt-out process.

As 9News explains, “Facebook rolled out three new components last week, including one called ‘social plugins.’ The feature interfaces with more than 75 websites, allowing users to ‘like’ or ‘recommend’ items or topics that interest them. The user’s name and picture is then displayed on the website for other Facebook friends to see.” If that seems a bit confusing, then you can see why Bennet is worried.

As any good senator does, he then huddled with a few like-minded senators, including Al Franken, Charles Schumer, and Mark Begich, to pen a letter. “We hope that Facebook will stand by its goal of creating open and transparent communities by working to ensure that its policies protect the sensitive personal biographical data of its users and provide them with full control over their personal information,” the senators wrote to Facebook execs. “We look forward to the FTC examining this issue, but in the meantime, we believe Facebook can take swift and productive steps to alleviate the concerns of its users.”