Indeed they are.

Beginning with the simple workflow:

1. Get many burner phones for cash.

2. Get many prepaid credit card for cash.

3. Sign up for many self-driving car services.

4. Targeted denial of service.

(I'm avoiding the very-slow-cruise-missile scenario because nobody wants to think about it.)

Not sure if you've tried lately, but when you pay cash for a burner phone, most retail outlets require a driver license to scan your information into their system. When you activate it, you need quite a bit of personal information.

It used to be really easy, but law enforcement is cracking down on the ability to buy and activate these anonymously for obvious reasons.

Are there ways around these? Sure, but it's not nearly as easy as you're proposing.

I got a burner phone at wal mart with no info recently.