I have been using Ed Teach for a while on any membership/ website that I didn't want to use my real name. It started when at a grocery store when they did not accept my card application for William Shatner which I liked to use, So, I needed something more obscure.
Since I am a big pirate fan, my favorite pirate is Black Beard, and Black Beards real name was Edward Teach. I shortened it to Ed Teach. It has been my user name ever since.