Are limpets a problem?

[ktomminello]

My tank is now becoming a limpet zone and I have absolutely no clue why!! All of the sudden I'm finding limpets all over my shells and rock. I had none yesterday and I found 4 on one of my turbo snails and about 5 more on random empty hermit shells and around my live rock. Can these limpets harm my tank?
Please help, thank you in advance!!