Forbes article on stealing bitcoins using phone system flaws.

Forbes has a remarkably good article on stealing bitcoins stored in Coinbase by using SS7 phone system flaws.

These attacks:

1. Have been shown to work by researchers
2. Have been used in the wild to commit crimes
3. Don't seem to be able to be fixed
4. Have the government's attention

For better 2-factor authentication (2FA),  Forbes suggests using an App, like Google Authenticator, or something similar 

Perry