If it follows you around it is on your phone. Spam sites like that place cookies and files on your system (phones, tablets, PC, laptops) and are triggered automatically.
I know security is a bitch but investing a couple dollars for some good antivirus/antispam software can give you piece of mind. I pay $79 a year and all my devices are covered (2 cell phones, 1 tablet, 1 PC and 1 laptop).
Apple products are by default extremely insecure.
Reading through this thread I don't even think it is a FH issue otherwise it would be more widespread. You guys have something on your phone sitting which you got from some other site and FH may just trigger it. I really recommend to clean your phones first through a security program outside Apple products. There are a lot of them available and please stay away from the free virus scan programs. They cause more problems than they solve.