Legal versus moral.
Legally:
We're still hashing out the legalities of what much of the net means in the American life (I'm assuming you're American here). It is legal to talk about tickling a minor, yes. Do not try to arrange to meet someone who you're made to believe is a minor though. Big no-no. Anyone that would try this would really need to get their head examined.
The TMF does not tolerate minor tickling posts, because of the liability issues. It's simply too risky.
But you did ask the legalities. And it is legal, strictly speaking to discuss it on the net (as of today, that facts may change depending on your jurisdiction and court cases that come down the pipe). But it is not welcome on these boards, just as Strel said. It is against TMF policy, and the membership as a whole frowns upon it.
Morally:
Can't answer that one for you. Morals are always relative, dependent on time, culture, and their own nature.
Socially:
See Strel's answer 🙂
