I used more than I can recall. The browser is a creative tool and being able to use all the creative features is great actually.
Just editing your profile picture is a good idea to do on the client side, why waste CPU on your server for example? I do photo editing a lot in the browser.
This is a feature that benefits everybody and the fact that it can be abused is unfortunate, but not as tragic as you paint it.
Photo editing could be designed in such a way that the JS code does not actually get read access to the canvas - it just specifies transformations.
It's becoming very clear I think that having this level of control for web apps is more detrimental than it is a positive. Leave rich apps to the OS, and keep the web as untrackable as possible.
Just editing your profile picture is a good idea to do on the client side, why waste CPU on your server for example? I do photo editing a lot in the browser.
This is a feature that benefits everybody and the fact that it can be abused is unfortunate, but not as tragic as you paint it.