What CEO is missing?  Vitalik?  Mihai?  I can guarantee you vitalik and Mihai are not missing.  They had money before this whole ether thing took off and they have way bigger plans than ether so they have nothing to gain by leaving.  Mihai owns Bitcoin Magazine and they're both involved in other ventures as well.

That said, they could leave at any time with those BTC and it would be perfectly legal.

Some people are hating too much on Ethereum and its founders.