said by BSAIII:Why does Verizon allow a caller id that is not a valid phone number. I have received 2 calls that show a bad number on the screen and when I use the TV widget to block the call I can't because it is an Invalid TN.
Verizon also needs to allow a bigger block list and wildcard blocking. For that matter they should have a white list option in addition to a black list.
You've encountered a caller that is spoofing caller ID, which is why it can't be blocked and when you call the number back it is likely an invalid number. Caller ID spoofing is illegal, but the people doing it obviously don't care. They're calling blocks of numbers with high-speed dialers, often violating the Do-Not-Call Registry restrictions also. Doing a Bing web search for "caller id spoofing solutions" produces many services that allow you to spoof. It's sad how people just like to break the law.
I agree with your second point (block or white list), and add that Verizon should allow blocking at the same time email notification is enabled. Currently, you can do one or the other but not both concurrently.