It happens and you can't do anything about it, apart from leaving. I really hope that pressure from ganking doesn't force you to leave, because the last thing we need is honest and good players leaving the server due to certain jerks.
A typical way of resolving this would be the good ol' "an eye for an eye", you gank them right back. But it's not what we need and in fact it'll only worsen the situation. Remember, if you rage and gank them back then you're no better than they are.