Transmittable cancer?

This is perhaps the weirdest thing I have read on cancer in a while. Apparently some cranio-facial tumours are getting passed on from tasmanian devil to tasmanian devils. All these red lights are going off in my head. First off, I was sure these little buggers were extinct. Second even admitting that the cells can "allograft", how the hell do they go from one snout to another, by making out? Third, don't they have an immune system? And fourth, the article finishes off talking about venereal sarcomma in dogs... As if there wasn't enough to worry about already. This is exteme parasitism of cancer. It has almost found a way to be alive outside of its host. Is it an organism? Reminds me of the endogenous theory of viral origin. And I thought nothing could surpass the identical quadruplets of armadillos in terms of mammalian weirdness...