You've taught me a new word. Yeah... it's not very nice. Going to have to master taking that one. Plenty more fish in the cyber-sea though so it shouldn't have to bug you for too long. As a matter of principle I shall never do it. I'll speak my mind then tell them "That's it... We've hit the deck...etc" then virtually walk away or cut them off, as appropriate; as one would do face-to-face. It's more mature.
When somebody drops you suddenly without saying anything and blocks you. It stinks and is a spit-my-dummy-out-juvenile way to behave, imo, but hey-ho it's the internet!