The Linux kernel developers have switched links in the documentation over to HTTPS. The move aims to prevent man-in-the-middle attacks against kernel developers, luckily no such attacks have occurred.
Mitm RSS
Mozilla and Google have taken measures to invalidate a root CA certificate from being used by the Kazakh government in Firefox and Chrome to intercept users' secure HTTPS connections to websites.
Google has announced that it will begin blocking any sign-in attempt from embedded browser frameworks from June as part of an effort to protect users from man-in-the-middle attacks.
SSL certificates exist to increase security and prevent snooping on your browsing sessions. Gogo believes you shouldn't have that and appears to be intentionally performing MITM attacks on its users.