I don't like being tickled at all, but I remember being held down and tickled by cousins. I think tickling in very short 1 second bursts is ok, though. Like, tickling where the baby can easily pull a way and allowing baby to pull away is different to me than being held down and forcibly tickled. To me, that gives the child a chance to easily move back for relief, and not come back if he/she doesn't want to. (I do that to my kid, and he always ALWAYS comes back with squeals of delight and anticipation for more. His body language tells me he doesn't mind.) To me, holding kiddo down and not allowing him to get away is taking away his choice in the matter.
Meh. My monkey's skin is so soft we don't usually do tickling because belly kisses are much more fun. His skin is yummy.
After watching my husband's brother hold down a 3/4 yo friend of the family and tickling until the child was yelling "Ima pee on myself!!!!" made me realize to never have my kid around him unsupervised. He can't seem to play/enteract with kids without mercilessly tickling them.