Level 1
Every week I see a browser allow adware through such as the infamous "Your computer has been hacked" popup usually in parallel with the computer speaker being turned into a loud buzzer.
Apart from using an adblocker, is there nothing the browser writers can do about this? For whatever reason this sort of thing appears not catchable by the traditional AV/malware apps so it really is up to the browser writers to intercept this malware channel.