You can grant access to different "applications" to make use of your profile. One such example is Winter Bash, or metasmoke a.k.a. Charcoal.
Theoretically you should be able to revoke/remove this access, but that has been broken for a while now.
What bugs me is the inconsistent placing of the button. Can we please align it to the right, regardless if it is on its own row or not?