It is and it is not. The rule is simple: think before you click. Mobile learning is not like running with scisors but is can be. On a very high level you just do not plug in mobile devices to your corporate computer and you do not connect to the same network.
As BYOD is more and more popular the risk is even higher. It means that your own phone in the corporate network should be secured by you. You need to make sure you have protective software on your device, do not install software that
is not authorised and do not get fooled. The government organization will not send you information that they want to give you the money back, they will use post.
In all of the cases: Think before you tap!