Don't lick the rat poison!

Show of hands please, how often did you have the following conversation? On which side were you on? Either way, what did you learn?

they: That looks pretty tasty.
me:   Yes, please don't eat that, it's rat person.
they: Can I at least lick it?
me:   What?! No! Why would you even want to?
they: Because everyone says it tastes sweet!
me:   Yes, it's sucker coated, so the rats don't become suspicious right away.
      Simple trap for simple minded animals.
they: What if I carefully lick away only the outer layer?
me:   (dafuq?!) DON'T LICK THE RAT POISON! You won't know when to stop! 
      That's how it's designed to work!
they: Ok, ok, fine! Understood. *Sheesh*, don't get your knickers in a knot, 
      buzzkill.

some time later

they: *Ow* my tummy aches.
me:   Why's there a bowl of wet rat poison on the table?

It’s always the same discussion with every social network (instant messenger, cloud service, online game, Microsoft product, …), isn’t it? Once you return to the table, you’ll find your warnings ignored, everyone is sick and miserable but somehow they still keep licking, asking you to join the feast or try to convert each other to a “better” brand of rat poison.