I've had mine for almost 7 years and they haven't moved at all. It kinda depends on where they are and how they are done. Done right, they don't do it. I know tons of people that are all the same, they have no change. I mean, yeah it can happen, but I think it's more that a few are unlucky. I knew one girl who got her navel done and the guy messed up so she woke up the first night feeling a tickle on her stomach and it was bleeding. It really depends on the elasticity and rejuvenation rate of your own skin. Kinda the same concept as stretch marks, some women don't get them because of how their skin is. But I have seen tattoos that went all out of whack and it was just weird. Arms don't really gain and lose size like the rest of the body so you don't see much change with those.