Those phones which can connect to the Internet are the easiest devices to hack. This is because they are on all the time.
Unlike a computer; be it desk, lap, tablet, which are shut off when one is finished using them to be turned on when one is ready, Smart Phones are always on.
The mal ware detectors you use to protect your other devices are not on your ‘smart phone’. Hence, anyone can virtually get into your phone, do what they please, and get out without much dislocation.
Added to this, many people who have Smart Phones are not particularly computer savvy. They will connect to a site to see a movie without thinking for one second that they are putting themselves at risk.
Those of us who watch programs and movies on line will constantly see warnings that this virus was blocked or that malware was blocked by our detector programs. Those on the Smart Phone will not.
If people kept their Smart Phones off until ready, aware of protection programs they could implement when they switched on, less would be hacked.