Token holders don't count. Flo Rida doesn't give a sh*t about bitcoin...his agent or someone just said "do this to get exposure". Much like owning private keys, if the celebrity doesn't own a wallet, they're not even close to being a bitcoin owner.
I haven't heard of ANY celebrities talk of bitcoin.
And on the non-celebrity list, Sean Spicer (Trump's Press Parrot, err Secretary) posted his bitcoin address on twitter back in January, then he deleted. Some people think he may have been verifying his identity with the post.
Article: http://gizmodo.com/did-sean-spicer-probably-didnt-tweet-a-nefarious-bitcoi-1794862780
EDIT: There's speculation that Spicey didn't actually post the bitcoin address, but that someone else did...for some unknown reason. Other side of story >> https://medium.com/@jimmysong/no-sean-spicer-didnt-make-some-secret-bitcoin-transaction-94b4851844b5