We’re revisiting the topic to remind you once again: use caution online and in the social media world.

The reality is, when you create a personal presence in cyberspace, you must always assume that nothing you do will be private, no matter what privacy options you set. An ongoing investigation by the Wall Street Journal underscores our point. It found that one of the fastest-growing businesses on the Internet is the business of spying on users.

The Journal’s comprehensive study assessed and analyzed the broad array of cookies and other surveillance technology that companies are deploying to track Internet users. It revealed that the tracking of consumers has grown both far more pervasive and far more intrusive than is realized by all but a handful of people in the vanguard of the industry.

These findings bring us to four principles of smart Internet and social media use that cannot be overstated:

The Internet and social media are convenient and powerful communication tools. But like anything powerful, they must be used with care, and with an appreciation for their risks and possible unintended consequences.