Most surge protectors only consist of an El-cheapo circuit breaker and a couple of undersized piss ant MOVs. In the event of overloading, ie plugging in too much stuff, it's designed to disconnect all sockets from the mains (same as your main breaker panel). In the event of a drastic overvoltage, the MOVs are there to shunt the offending line to ground/neutral.
For the most part, surge protectors are only good for port multiplication, rather than surge protection.