Google isn't satisfied with securing Gmail itself from prying eyes; it's blocking sinister add-ons, too. The email service now supports Content Security Policy, which prevents web extensions from running code that could bypass security or otherwise wreck your day. The move shouldn't create havoc with honest add-ons, but Google acknowledges that some of them might need updates to work properly. That's a headache if you rely on these extras to sweeten your Gmail experience, but the move could be worth the tradeoff if it prevents someone from snooping on your messages.