Some people on this kind of forums say that they are addicted to masturbation, pointing out that for some of them it's easier to quit porn compared to masturbation.. The thing is though that I've never heard of regular masturbation (the kind that's been practiced by humans and some animals for eons) causing addiction-related brain changes - on the other hand porn CAN and DOES.
Saying masturbations is addictive in the same way as porn is missing the point of what an addiction actually is. Sure, it's hard to stop masturbating and/or orgasming, but it's also hard to stop eating, drinking and breathing for example, yet we don't really consider the latter examples as addictions.
BTW, I'm not a big masturbation advocate (I've only masturbated like 4 times during this porn free streak), but I do think it's unnecessary to feel that the urge for a release (even by your own hand if real sex is not a possibility for a long time) is something that's indicating an addiction.
You DO want to quit masturbation for a while if you have PIED though, but that isn't ment to be permanent...