I'm with you - But in the US I believe this depends on the state. The "To catch a predator" show was specifically done in areas where the law included "intent" as a crime, rather than the actual crime IIRC.
The arrests on that show also usually result in dropped charges or even the suicide of an alleged predator. We shouldn't be condoning these kinds of tactics anywhere.
https://en.wikipedia.org/wiki/To_Catch_a_Predator#Criticism