From AFI’s set at Cleveland, OH’s House of Blues on 06.20.17, live performances of songs keep appearing! As you may know by now, AFI debuted two songs at the House of Blues; those songs being “Anxious” from “Burials” and “Who Knew?” (one of my favorites!) from the Black Sails EP. Now, when I saw debuted, I mean they have NEVER played these prior to this date. Some may argue that, but Davey actually says at the end of the video, “Cleveland, some of you know that fucking song!”.
Davey also said (to confirm) that was only the second time he’s ever sang that song. The first time being when they tracked in back in '99. Check it out below! Thanks again to “You Don’t Know Music” for recording this!
Also, if you’d like to view the original thread on the House of Blues show, go here. I made this separate thread because I felt it fitting. This video is in such good quality and entirety that I felt it needed its own branch of discussion. 
You can also catch another version (from Portland, ME) of “Who Knew?” here. The quality isn’t as good, but still a very nice video.