In Star Trek they had communicators and tricorders which is basically an equivalent to todays smart phone.

The reality vs. the science fiction is smart phones are much worse then what was presented in the Star Trek universe.

In Star Trek their communicators were use for just that communications. Our phone are used for personal surveillance. Some naïve people would argue that the surveillance is only for advertisement purposes to sell you products you are already thinking about but If someone would like to test it, seriously talk about "replacing" the government and watch to see who shows up at your door. I got a crisp $50 that at the very least you will be put on a list!

As for the tricorders, they were tools to help. Our smartphones are trackers and attention whores designed to give you a cheap dopamine hit and keep you coming back for more. Any useful tools on them are either monetized or you are selling yourself and information.

binaryblob said is correct, its not the technology, its the people behind it that are the danger. And I 100% believe they are very very dangerous.