The September 2014 issue of Consumer Reports has one of their most disappointing articles. It's called "Free Wi-Fi takes off at airports" and is on page 10 (it's not available online).
The article is a huge opportunity missed. Completely ignoring security, it's full of useless statistics. For example, readers learn the percent of pleasure travelers that connect to the Internet while at an airport. And, if that wasn't useless enough, the magazine also reports how many of them used Wi-Fi vs. 3G/4G.
The first issue with airport Wi-Fi is learning the name of the trusted wireless network(s). I don't travel a lot, but I have yet to see an airport that advertises the name of their public Wi-Fi network. Should travelers in Denver connect to a network called "Denver-Public" or is it a malicious network run by a bad guy sitting near gate 6?
And, if the airport doesn't offer Wi-Fi maybe the airline does. While waiting for a Delta flight, how can travelers tell if the network "deltawifi" is run by the airline or a bad guy?
On top of this, it should be mandated that every article about public Wi-Fi warn about evil twin networks (think of the mutual fund warning that past performance is no guarantee of future success).
An evil twin network is just what it sounds like. It's a wireless network run by a bad guy that has the same name as the network run by good guys (an airline, for example). Evil twins are possible because anyone can name their Wi-Fi network anything.
There is no way to distinguish an evil twin from its legitimate sibling.
VPNs are a great defense from open Wi-Fi networks but only if the network is run by good guys.
A VPN doesn't come into play until after an Internet connection is already established. An evil twin network puts a bad guy between the victim and everything they do on the Internet. You might as well have someone standing over your shoulder with a camera recording everything you do.
To the best of my knowledge, the best defense is to simply assume a bad guy is watching everything you do online and act accordingly. If possible, don't connect a computer containing important or sensitive files to a public network. Also, as a rule, 3G/4G is safer than public Wi-Fi. Not necessarily safe, but safer.
The Consumer Reports article also describes services that charge for wireless Internet access. The problem with this is that, until you have an account, you can't trust any public network. So, unless you sign up ahead of time, fuggedaboutit.
The only downside to free airport Wi-Fi that Consumer Reports mentioned is that the connection might be "sluggish". This is like an article about locks saying that the only downside to not having a lock on your front door is the footprints on the carpet left by the thieves that steal all your stuff.
If you want carpet cleaning information, Consumer Reports is probably a good source. But for computer advice, not so much.