It was creepy enough when Google (NASDAQ:GOOGL) launched its contextual advertising system AdSense. Using keywords found in text of websites you were reading, Google would display banner ads that correlated to the article's content. Read up on health care and you're likely to see ads about health care products. Find an article about tools and you'd get ads for hammers or table saws might pop up.

It then started scanning your email and offered up ads based on what your private conservations were discussing.

Yahoo! took contextual advertising to search with what's called retargeting advertising, or giving you ads based on your search history. It still creeps me out to see ads on sites having nothing to do with what I'm currently looking at but know I recently searched for the term.

More recently Apple flipped through your phonebook with its Path app and collected the data from it while Google (again!) bypassed privacy settings in Safari.

Big comfy couch
Now telecom giant Verizon (NYSE:VZ) wants to go even further and eavesdrop on conversations you're having in your living room and offer up ads based on what you've been discussing. In a patent application describing the technology, Verizon says that if the conversation detection system senses an argument, your TV might display ads for marriage counseling. Canoodling on the couch? Romantic getaways or contraceptives might appear. Playing with Fido on the floor? Dog food ads would show up.

Worse, the system can detect whether or not you've got a smartphone or tablet computer and could push an ad directly to those devices. Verizon can definitely hear you now.

Name, rank, and serial number
Although Verizon filed the application early last year, it was only recently published due to laws requiring all patent applications be published after 18 months. FierceCable was the first to catch the notice and pointed out researchers have long wanted to use Microsoft's Kinect cameras for the Xbox 360 to target ads and shows for viewers. Subsequent reports have pointed out that cable operator Comcast filed a patent years before for technology that would recommend advertising based on who was in the room, while Google TV sought to figure out how many people were in the room watching its broadcast.

Loss of privacy begins with small steps
This move to monitor what we do and now what we say should be concerning to privacy advocates, particularly in light of the FBI's poring over Generals Petraeus and Allen's email messages looking for evidence despite no crime having been committed. Former National Security Agency employee-turned-whistleblower William Binney says U.S. citizens are already under almost constant surveillance and the FBI collects and stores virtually every email you send. And given that law enforcement agencies want Verizon, Sprint, and AT&T to record and store all of your text messages for two years in the event a crime should occur at some time in the future, the ability of telecoms to monitor what's going on in your living room and bedroom (most of us have a TV in the bedroom, no?) will undoubtedly also create a mandate to record and store what they find there, too.

Google and Facebook routinely push back against encroachment on privacy invasion, even as they're often criticized for violating it for their own purposes, but there comes a point when pushing advertising crosses the line from delivering relevant content to being a creepy pawn for Big Brother.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.