I don't think I am being listened to or read by an actual person when I use FB or Twitter or the phone. That kind of surveillance is a physical impossibility. Rather it is data collection algorithms that mine what we post/say and then feed that info (for money!) to advertisers, data companies etc. I'm with @lucylin and @thinkingishard in trying to reduce my online footprint. For instance, I now use duckduckgo.com instead of Google. It won't track your searches and allows you to install an app in your browser to prevent tracking of the sites you visit.

It can be very informative to find out what FB has on you. Head to Settings and click on 'Download a copy of your data'. You may be surprised at what is listed when the download is complete!