My understanding of Facebook is that it is just a platform. You offer your identity using the platform and someone accepts you as a friend. The privacy of that relationship needs to be respected by the trustee of the platform who has access to all this personal data. This should not be used for financial gain!
If someone posts anything publicly then this is not the problem of the trustee. However, Facebook is mostly used by users to boost their image or for enhancing their public profile. Therefore, can such information mostly cannot be depended to upon for marketing and political campaigns? There are some people who completely exist within Facebook while some are invisible phantoms.
However, using the platform to spread harmful elements is a different subject. Due to connectivity, people of different backgrounds and cross sections of the community are exposed who have different levels of understanding. That needs to be addressed.
As men who totally changed their societies and the world, Buddha, Jesus and Mohamed were born and preached different types of societies that had no connection. Such societies were mutually exclusive in time and geography.
For example, Buddha lived and preached a comparatively advanced society that existed in the East. Therefore, he was able to preach about meditation, control of mind and materialism of needs that are required achieve Nirvana. Mohamed was born to a very different society. Mohammed preached the 5 pillars to establish discipline in that society. Jesus was in a sectarian society and most of his sermons are about forgiveness not unlike the mental state of letting things go as Buddha preached.
What these three had in common was tremendous influence and power over people because they could see deep into them.
The fundamentals of reaching out to the society required intuition and understanding how the variables are in line at a moment. This was something that can be seen in those three figures and why they reached the hearts and minds of the societies they lived! There were others who failed to do that and have been forgotten by history