If you register your number on the do not call list, there are restrictions on who can call you. Generally, random telemarketers are prohibited. There are many exceptions (charities, etc). Learn more here:
https://www.donotcall.gov/
I've had all of my numbers registered from the beginning. I report all violations - more to make me feel good than get any real results.
If the Fed wants to increase revenue without additional taxation (oops, that's the other party - this one loves taxes), they could start by enforcing and fining violators.