JuiceJacking - hijacking your smartphone data via public USB charging ports.

CSI:Cyber (S01E09) was about "JuiceJacking" where plugging your smartphone into a public USB charging station MAY allow your smartphone data to be stolen (see 3-minute clip below).

https://news.yahoo.com/video/csi-cyber-juice-jacking-014236264-cbs.html

Best defense against JuiceJacking is to carry your own AC adapter...

...and not trust any public USB-only charging ports.

Security researcher Brian Krebs wrote a column on this...
     http://krebsonsecurity.com/2011/08/beware-of-juice-jacking/

... in August 2011.  At the time, iPhones/iPads/iPod Touch were vulnerable to JuiceJacking (up to and including iOS v6).  As of iOS v7, Apple added a "Trust this Computer"...

...query when plugging into an unknown USB data port -- answer "Don't Trust" or "NO" if it's not your computer; your iDevice battery will still recharge).

So, an up to date iPhone is protected.  Not sure about your Android / Windows Phone / Blackberry ?  Bring your own AC charger as public AC outlets with your adapter are OK.

More up to date info from a Google search of "JuiceJacking":  
     https://www.google.com/?gws_rd=ssl#newwindow=1&q=juicejacking