What could that nice president Trump do with this alert thing?
Could he block all interpersonal communication?
I suppose with a flood of messages someone could create a Denial of Service attack.
I know once in awhile we get alert storms from work and 150 or so message come in 1 second apart, and you have to "Read Now" or "Read Later" as they come in before you can use the phone ... well, at least that's how it works on my flip-phone.
Locally, someone hacked the emergency sirens a few years back and kept turning them on until the city had to disable them until a more secure system was put in place - at a big cost.