Should not set it to nonsense, but rather low-entropy. If its unique, someone with access to old (browser, probably) crash reports might be able to cross-refere

Should not set it to nonsense, but rather low-entropy. If its unique, someone with access to old (browser, probably) crash reports might be able to cross-reference. Plus, not too long ago browsers did not care to sanitize the path for input[type="file"], so some websites remembered your account name somewhere in their database.