"But Cryptogee, if the community come together we can fork out Justin if he tries anything we don't like!"

LOL.

No you can't, because that would require the top 19 witness votes, which can be vetoed by the @freedom witness (now owned by Justin), and of course he can use that very same account to vote in his own witnesses.

Technically you need 2/3 plus 1 of the witnesses to do it not 19 and to be precise it doesn't matter if a big account replaces the top block producers you can still create a fork with a minority witness (anyone running a node can create a fork).

The real issue is what chain do exchanges recognize as "Steem" and where do the users transact.