Topping tech headlines on Wednesday was Facebook's pledge to crack down on inappropriate posts, most notably those that offer to sell firearms.

The social network has recently fielded complaints about private sales of firearms—"one of the many areas where we face a difficult challenge," the company said. To plug that leak, Facebook introduced new educational and enforcement efforts to users discussing the private sale of regulated items.

In other news, Yahoo will ditch the option for users to sign in with Google or Facebook IDs and require that they use Yahoo IDs instead. The switch will roll out gradually and affect services like Flickr and Fantasy Sports. But once it does, there will no longer be a "Sign in with Facebook or Google" option on the Yahoo log-in page. In other Yahoo news, the company yesterday announced the acquisition of customization tool Vizify, which will shut down as part of the deal.

Meanwhile, news reader Flipboard has acquired rival service Zite from CNN. As part of the deal, CNN will now be available on Flipboard. According to the reader service, the acquisition addresses user concerns about finding content "about the things that matter to you." The existing Zite apps for Android, iOS, and Windows Phone are still available for now, but will shut down in about six months.