Banning Yasuo from your first pick toplaner is completly justified

first pick........... enough said get down voted to hell please and uninstall

The main issue should be that you can't use the ban on an OP champion.

However, there are so many at the moment that many will slip through the ban phase anyways.

Depends on the reason you banned him

Actually Yasuo mains on your side can be nearly as bad as having one on the other side (along with Riven mains, Master Yi mains, etc.). :p

Also, it depends - is it truly first pick overall? Or first pick on your side?

So he can't pick yasuo first but can pick another champion first? Banning another person's champion is harrassing and trolly sort of.