> They literally just mean things like filling out forms. Implicitly or explicitly you have to give Firefox permission to store and reproduce the text you type in this very textarea so that it can submit the form for you.

If they mean that they should say that.

But also it doesn't seem like they would need permission to store data locally, on your own computer. If it's a matter of using Mozilla Sync, then the TOS would apply to Sync and having a Mozilla account, not for using the browser.