A giant 'Reply All' via Facebook.

The potential message is: “We’ve Moved”. I’d like to send it to anyone that has ever Liked or Friended us.

Surely this is possible, isn’t it?

Create an event and invite your entire friends list.

Oops, NM : GQ

“Ever liked or friended us”?? Are you suggesting that it is also to go to people that used to be your FB “friend” but have explicitly unfriended you? I am pretty sure it is impossible, and would consider it a bug in FB if you managed to find a way to do it. If I unfriend somebody I don’t expect them to continue sending me stuff.