Manipulation of users is one of these malicious functionalities. Here are examples of programs that are designed to do this by taking advantage of human psychology.

We have a special page for Addictive programs, which also take advantage of human psychology, but in a much more elaborate and dangerous way.

• The Femm “fertility” app is secretly a tool for propaganda by natalist Christians. It spreads distrust for contraception.

  It snoops on users, too, as you must expect from nonfree programs.

• The Jibo robot toys were tethered to the manufacturer's server, and the company made them all cease to work by shutting down that server.

  The shutdown might ironically be good for their users, since the product was designed to manipulate people by presenting a phony semblance of emotions, and was most certainly spying on them.

• “Dark patterns” are user interfaces designed to mislead users, or make option settings hard to find.

  This allows a company such as Apple to say, “We allow users to turn this off” while ensuring that few will understand how to actually turn it off.