3 days after launch, we received a cease and desist letter from SecretementVotre (secretly yours, in french) asking us to basically close the service : http://www.businessinsider.com/secretpoke-secretementvotre-2...
We had more fun than fear, and actually blogged about it. Even playing off with the title: SecretementVotre wants to screw up SecretPoke.
Ideas are a dime a dozen, execution is everything. At any given time, 10+ people around the globe are thinking about the same revolutionizing ideas... The only difference between France and the US is that you cannot "protect" an idea in France... so nothing happened.