Article at link:

http://www.forbes.com/sites/laurashin/2016/12/20/hackers-have-stolen-millions-of-dollars-in-bitcoin-using-only-phone-numbers/#3e024ad522db

Lessons learned:
2FA using SMS is badly compromised.
You can't outsource your computer/cryptocurrency security to a 3rd party like your phone carrier. It's a recipe for disaster.
Hackers are targeting prominent bitcoiners - but it's only a matter of time for the rest of us.
Thieves are impersonating prominent bitcoiners, asking friends for "loans" of BTC (etc) - which just means more victims.
It's not just bitcoins - bank accounts and everything else are vulnerable. (And you can't fix those with a Trezor or paper wallet.)

What else?