For the most part we are or choose to be anonymous on the Internet. Using pseudo names, Facebook privacy, there are things we can control.

My self thinking is that what do I read or collect the the "Big Brother" types would ever want. I am not even a blimp on their radar.

I would worry if searches for "target" words and threads popped up on homeland security or secret service types words or events were searched I would be found.
As far as those lurking, many people do not want to post, but do enjoy reading experiences.

The companies could be advertisers, bots for saving the threads which I do not care for, or even health care company's reading how side affects may bother us.

As far as personal worry, I don't think there is any malicious companies reading us, little we say can be of interest. We are not political, the nRa, liberal or conservative forum.

Just make sure if there is a forum you like to post, you feel as anonymous as possible,