My Bialetti Moka has porous holes that seem to go beneath the surface. These pictures show those small holes.
Safe or not, I think it comes with the territory. I've had mine (2 actually) for 5+ years now and it is quite pitted, itself. I think this is naturally what happens when (mineral) water boils against metals. I don't know how relevant it is, but I tend to get right to enjoying my coffee, and neglect the moka. Coffee (acidic) seeps down into the reservoir, and I suspect that might contribute to the pitting. I have no doubt that I've drunk this metal, but thankfully being a food product it is a safe metal; they don't make these things out of lead, you know. I'm no chemist, biologist or doctor, but I have had a fair amount of experience with a couple of mokas and friends who also use them, and they all inevitably pit. I don't know if it's safe, but it seems to be the norm, and I have yet to hear of any recalls. Bialetti is a reputable company. And the FDA (or whoever) wouldnt approve a food product that was dangerous.