BEWARE of ADWARE/SPYWARE/MALWARE !!!
600% Sound Volume extension breaks MFA functionality on kongregate.com (after signing in with username and password another window should open to enter security code received by email, but it doesn't when this extension is enabled).
An add-on that supposedly boosts audio volume shouldn't break website sign in process. Unless it's trying to do something shady in the background, like stealing user credentials or something.
If you care about your privacy, I recommend to disable and remove this extension ASAP.