I have dozens of databases one for every different application other then in a couple cases two for a single app, I have always created a new user for each database , assuming that if (a) or one database was compromised , then if using the old brute force this would have to be repeated for each database.
It's getting to the point of monotony when backing them up, although I have been using navicat for a couple years to administer them, when I have to do something quick in terminal accessing the sql server and remembering each is now a futile task.
What do you do ?