"Coordinated attack" might raise more than eyebrows with the legal departments of the companies you've called out.

>Over the next 27 hours, in four distinct waves, all of them tried to use my VoIP (SIP) server to place phone calls on my dime.

As you've clarified in your comment here the companies did not do this. Compromised machines on their networks, controlled by third parties did it.

No comments, but thank you for sharing and staying vigilant.

A question: why are you writing this with an LLM? Can you not write with your own words, at least on HN?