We all know that the internet has become saturated with social networking. If you can read it on the web, chances are you can also “Like” it. It’s only natural that, if you share something, Facebook or Google will know that you visited that page. It’s also likely that they’ll use that data to sell advertising. What most of us don’t know, however, is that those same networks can track your visits to many pages even if you don’t click on any sharing buttons. Enter Priv3, a new extension for Firefox that only allows your visits to be tracked when you want them to.
There is a lot of information available online - but the reality is that anyone who can type can post something online. It may or may not be true, and it can be very difficult to determine whether or not something you see online is from a reliable source. This applies to photos and videos as well as text - many people think that if they see a picture of something, then it must be real - but photo (and video) editing software can make things look real that in fact are not. Think about a movie with really good special effects, for example. Because of this, it's important to remember that when you post something, true or not, there will be people who believe it and others who don't. In addition, if you post something that is meant to be sarcasm or a joke of some sort, be aware that many people might not see it that way. Be very cautious with the words you choose to use in your posts online, because you never know who might be reading them and taking them at face value.
Remember that when you post something, it can be found later. While current technology might not be sufficient for someone to identify you by using face recognition software, it's very likely that software coming out in the future would have no problem identifying you (or someone else) based on, for example, a blurry photograph. The same goes for speaker identification software and other technology that can be used to identify people. As time goes on, the technology improves, so never assume that because something isn't possible today, it won't be possible in the future.
Once a tweet has been retweeted or a post on Facebook has been liked or shared, you can't delete it - neither technically nor legally. Once a web page has been crawled and indexed by search engines, there is a record of it. If you post something that shouldn't be made public, you don't have much time to delete before it's really not possible. Posting information therefore means giving up control over it.
The fact that you post boring things, like pictures of what you ate for breakfast, doesn't make you invisible online. Although it may sometimes seem like nobody is paying attention, advertisers are always paying attention, and data you post is collected by social networks and other businesses in order to tailor ads to your tastes and (hopefully) increase profits as a result. Maybe you don't mind that social networks are paying attention to your breakfast, but it's good to be aware that even seemingly insignificant posts online *are* tracked by somebody, often as part of a marketing strategy to increase profits.
Just because you aren't posting information about yourself doesn't mean that other people aren't. Lots of people post pictures from vacations, weddings, and other events that you may have attended. There could also be information about you online having to do with your job, for instance on a company web site. Even the government might be sharing information about you without your knowledge. Gerald Friedland recently commented on concerns about publicly available statistics from surveys, the census, and other government sources.