"Hey wanna gift each other mystery skins?" - How likely am I to be scammed?

Hey League folks, I've had a question for a while now that I can't seem to get an answer to. I'm pretty sure most of us have had a situation where someone messages us and says "wanna gift each other mystery skins?", and I was wondering what the likelihood of gifting a skin and not getting one back is. You see, I've been scammed on various other games through similar means and I was wondering what the overall integrity of the community is when it comes to this. Also, is it enforceable by Riot or bannable to not send a gift back? Before I give in and accept someones offer I would like to know what I could do, if anything, if it turns out I was scammed.

Also, what is Riot's official stance on this? Do they permit/encourage swapping gifts like that?