CoinFire is not ran by an individual named Mike Johnson nor does the owner of CoinFire work for the SEC. The reason mjohnsonbtc does not exist anywhere on the internet prior to September 2014 is because it's a trolling account. Mike Johnson is a pseudonym and the actual name of the individual that ownes BitCoin is Raymond Angel. See information on Raymond Angel below:  

https://www.crunchbase.com/person/raymond-angel
https://angel.co/startupguy
https://www.facebook.com/raymond.g.angel?pnref=friends.search
http://ray.vc/ (no longer active)
https://startupgenome.co/raymond-angel

Cheers