Were you upset when Facebook automatically tagged your photos and announced who you are to its millions of users without your permission? No worries, Facebook will soon know exactly how you feel.

For those sensitive to online privacy, the threat posed by facial recognition technology has not yet fully surfaced.

Face.com, a face detection and recognition service that equipped Facebook with the facial recognition technology, has announced an API release of a new set of facial analysis attributes, namely, mood estimation and facial expressions.

Mood Estimation

The API will estimate your mood automatically, with 5 values: Happy, Sad, Surprised, Angry, and Neutral.

Facial Expressions

Face.com expanded their set of available facial expressions from a simple smile to include the state of a person's lips. Now they can tell whether you are smiling, have your lips sealed, parted or kissing.

The market has already been shaped for this technology. Over 20,000 developers have already found uses for the API.

According to Network World, within days of the release, the API was used in a free Cartoonizer Android app to convert your photos and those of your friends into cartoon characters. Another application called Moodbattle allowed users to to compete for who has the angriest, happiest, saddest or neutral(ist?) facial expression on Tumblr. Since the API is offered for free, it is plausible that more developers will continue to play around with the APIs, said Network World. There is even a Sandbox Console for developers to tinker with the API without coding.

Back in June, Facebook quietly rolled out a facial recognition technology to identify people in photos uploaded on its website, and it has already spread controversy due to a number of privacy issues.

The feature has stoked concerns from users, privacy advocates, regulators and lawmakers as the feature is enabled for all 600 million users by default and suggests people's names to tag in pictures without their prior consent.

Users can only opt out from the service, as the default setting enables the facial recognition system without users' consent. Critics, including the Connecticut AG, contend that the feature should require users to affirmatively consent.

There is also concern over the inherent biometric data collection. EPIC points out that Facebook has the largest private database of labeled facial photographs. In all, EPIC thinks Facebook has 60 billion photos on over 500 million users around the world.

The big question is if it's really a good idea for a private company to possess biometric data that can identity at least 500 million people from their faces. The danger is that either Facebook will abuse it or that a third-party will get its hands on the data and abuse it.

Facebook acknowledged it should have been more clear with people during the roll-out process when this became available to them.However, a Facebook spokesman Andrew Noyes told The Wall Street Journal the company has received almost no user complaints, suggesting people are enjoying the feature and are finding it useful. He said Facebook had made the disabling feature easy and explained how to do so on our blog, in our Help Center, and within the interface.

This is not the first time Facebook has faced scrutiny from privacy advocates. Facebook previously had plans to make users' home addresses, mobile phone numbers and other personal information available to websites and application developers. However, Facebook suspended the plan after facing several objections from U.S. lawmakers and others.

Can convenience and security coexist? Or has the society grown insensitive about privacy in this network generation where online presence is a must? Face.com, at least, believes that most users don't mind being recognized automatically online.

Whether you do or not, you are probably already there. If you frown at that thought, Facebook will recognize and soon stamp your photo with angry.

If you think it's creepy, see Facebook Facial Recognition - How to Disable [Walkthrough Guide]