The problem is the issuer can revoke or cancel your identity/invitation up to a certain point. Someone else on here can probably explain it better, but I think if that happens you would lose the coins that you had locked after validation.
Yes but ... total reward from single invitation if your invitee become verified (3 epoch old), during last epoch was 33 + 98 + 198 = 329 iDNA - if you terminate the node you invited that is how much coins you are resigning off.
New node during 3 epochs will mine 388 coin and will get around 100 coins for validation = 488 coins. And he will loss 80% of that = 390 coins
My loss is quite the same as person i've terminated. So it's more like an extreme case scenario when someone terminates a node that he invited. It's not something that is commonly used for fun.
And it is suggested in FAQ to take invitation from someone you trust. Most often a quick talk is enough to know if you are talking with normal person or crazy bustard that wants to loss 330 coins to make you loss 390.
