When to use Bitwise Operators during webdevelopment?

Although I grasp the concept of Bitwise Operators, I can't say that I have come across many use cases during the webdevelopment process at which I had to resort to using Bitwise Operators.

• Do you use Bitwise Operators?
• Why do you use them?
• What are some example use cases?

Please remember that this question is specifically intended for use of Bitwise Operators in web languages.

My main use for bitwise operators could be relevant anywhere - representing a set of flags. For instance, you might have an integer in the database representing a set of security permissions for a user, and in your web app you would have to check those before continuing.

Those tend to only require & and | - e.g.

if ((permissions & Permission.CreateUser) != 0)
{
    ...
}

or

Permission requiredPermission = Permission.CreateUser
                                | Permission.ChangePassword;

Bit shifting operators are less useful in "business" applications in my experience.