I received a letter about a year ago from a constituent who doesn’t use email. He is a technology professional who believes that online communications are taking us to a bad place. He persuaded me to read “Surveillance Capitalism,” a well-researched call to arms against overreach by the Googles and Facebooks of the world.

Google started with the wonderful mission of making all the knowledge in the world accessible to everyone. I personally love Google for giving us so much progress towards that mission. I remember spending afternoons in the bowels of the Boston Public Library to dig out facts that I can now find in seconds.

Tools like Facebook and Snapchat enable us to connect to friends and family in ways that I use less, but still appreciate.

In “Surveillance Capitalism,” Shoshana Zuboff argues that during the .com financial crunch, Google had to turn in a more lucrative direction. Venture capitalists pushed them to monetize the data that they were collecting about user search activity. They began targeting advertising towards us based on our apparent interests.

Driven by the advertising profit potential, the company has moved further and further in the direction of collecting data about individuals. Google has created enormous value for us by rolling out great free products like Gmail, Chrome and Maps but at the same time has gathered more and more information about each one of us as individuals. By creating wonderful tools for developers like Google Analytics, Google has induced developers to build connections that share data with Google into a large fraction of the mobile apps and websites in the world. By now, Google has a pretty good guess as to where billions of people are, what they are doing, and what they are thinking about.

Facebook and many other emerging companies are following Google’s basic business model: Give users something and take back a lot of data about each user, including data that the users have no idea that they are providing. We all give thought to what information we put into our Facebook profile but we usually think less carefully about clicking a Like button and give no thought at all to what we might be divulging about our personality by how long we look at a particular image or the number of exclamation points we include in our comments.

And, of course, none of us read the fine print in privacy policies, which Zuboff points out should more properly should be called disclosure policies since they usually give companies broad license to share much of what they know about us with third parties.

We slowly get habituated to the idea that we are being minutely watched. If government regulators inquire about a particular data-sharing practice, the powerful technology lobby delays and dilutes proposed new rules. Meanwhile the companies move on to new methods of intrusion that the regulators haven’t even figured out yet. As the “internet of things” expands and our appliances and our cars and our homes share more real-time data with commercial entities, the intrusion of data-gathering capitalists will become more and more pervasive.

Surveillance capitalism refers to this basic pattern of making money off increasingly minute and “unpermissioned” surveillance of individuals, which verges towards control of individuals through behavioral nudges.

I remain grateful for the value that the technology companies have created for us and hopeful about the future, but I do think that Zuboff effectively raises a question we all need to ponder: What do we need to do to make sure all this doesn’t go to a bad place? At this point, I don’t know the answer to that question.

I’d welcome your thoughts online at http://willbrownsberger.com or william.brownsberger@masenate.gov. Or, if you prefer, just send me a letter at Room 504, the State House, Boston, MA 02133 or give a call at 617-722-1280.