Help! My Youtube account has been hacked and one of my videos has been replaced. Also they replaced my About me and Hobbies and subscribed to things and favourited videos AND REMOVED ALL MY FRIENDS!
It isn't easy to guess if it is like this: jA82'jFk,JK
But it is easy to guess if it is like this: ilovecookies
And there's lots of programs that can easily hack into accounts and give you passwords.
Those are brute force attacks, I would imagine that Google have a "tarpit" which would avoid someone making thousands of requests on a single IP, which would be required to hack such a password. For reference Google blocks me if I do too many sums. I'm not saying that you shouldn't worry about an easy to guess password, just that I'd be surprised if this attack had been brute-forced. Far more likely this was due to a keylogger or the OP just not being cautious enough with their security details.