[_nub3]

> Routers will accept a "shut up" request. If A wants to block B, it sends to a router on the path, the router pings A to validate the source, and then blocks traffic from B to A for a few minutes. This also contains DDOS attacks. Routers can forward "shut up" requests to the next router in the path, for further containment.

This is an invitation to silence unwanted users by certain governments.

[albuic]

You might have missed the "from B to A" in the parent comment which is quite important. Moreover governments have other (legal) ways to silence users.