I would like to start by drawing a situation, you walk in a desert leaving behind your foot prints in the sand and likewise whenever you talk with anyone in physical life you end up leaving behind an essence of yourself.
In real life these essences are erased away by the forces of nature, like wind in case of sand or human memory in case of physical conversations.
Likewise, when you are using Facebook, you are creating a lot of data points. When you send a friend request to anyone, you end up creating a data point. When you send a text to anyone you end up creating a data point. The only difference is that in the virtual world these data points are not erased and are used by Facebook to monetize the platform.
There are arguments also being given that Facebook shares the data with third party and that is a violation of your privacy. When we register on Facebook or for instance any technology platform we agree to certain T&C, in case of Facebook such data sharing is expressly stated in its T&C. Once, you have agreed to it, there is no reason for you to be unhappy with the way the data points you create are being used by Facebook.
Even in USA Presidential Elections, these data points were extrapolated on a large scale to sway the elections in a certain direction. I also find this argument futile as we are anyway being manipulated on an everyday level to buy products based on Facebook ads.
What I wish to point out is that, it is only this data collection of Facebook which has helped us find almost instant help in cases of natural calamity, or get to know the status of our loved ones stuck in remote areas.
The future I see is that crime will be prevented before it even happens due to the way Facebook processes data.