Exactly, both reference pretty much the same lists (which is what actually does the ad blocking.)Good lord, what a thread necro There's no question of "safety", it's a matter of why bother? These extensions are nothing without their lists, so why have two extensions checking several different lists when you can just have one doing it? It may or may not slow things down, but it's just pointless extra work for both the extensions and the browser. K.I.S.S I always say.