[sulam]

If his modem is actively interfering with your network I could see that this is critical. If he has been hacked and is actively DDOSing sites, that’s critical. We can debate the correct response in those cases (getting on the phone and calling seems to work really well when you want people to pay you, as does turning off service).

Unless I’m misunderstanding, this was not causing such a problem. Casting it as a customer good is rhetorically amusing, and probably holds water with people who are predisposed to agree with you, but I can make any number of morally bankrupt decisions using exactly the same logic. You have simpler ways to deliver this message, that do not cause nearly as much harm to your customer and do not require you to intercept and modify their traffic.

[lucio]

It's true that if there's a vulnerability discovered, and you have 50000 modems with the vulnerability, you cannot wait for the modems "to be hacked" to act. It is reasonable to try to replace EOL modems ASAP.

[sulam]

In this scenario do you honestly believe the best course of action is to insert a popup on web pages? If you are truly concerned you will act to preserve your network for all customers by blocking traffic from the problematic modem and then call the person. This is legally less risky than doing traffic inspection. (Losing common carrier status would be a very big deal.)