I was amused when I listened to the Radio 4 You and Yours program when the first thing that was said with regard to the risks that you run when you use your smartphone is that of loosing it or having it stolen.
This obviously was not "sexy" enough and you can't sell anything to get people to take more care in not leaving their phone on a train or putting it in a situation where it can be "lifted". It was a chance for the "technical experts" to go on about public WiFi and having your traffic "sniffed". There was a solution (or app) that I guess the experts could sell you for that!
Android systems seemed to get a bad rap for security, as opposed to the Apple iPhone. This was cited as being due to the fact that Google (Play) do not "lock-down" the design and distribution of their apps to the same degree as Apple.
The MAIN THREAT comes from Social Engineering, nothing unique to Smartphones. If a website can convince you to enter your personal details then is is down to your own stupidity.