Have you ever Googled yourself? We all know that a pile of information about us exists online, but it never really becomes clear until you put your name or online handle into a search engine.
Looking for something a little freakier? Try a Google image search.
A digital footprint is an inevitable side-effect of your life online — pretty much everything you do online is stored somewhere.
The trail that makes up your digital footprint consists of data that you've willingly put online; data about you that someone else has put online; data not available online that you've created; and data not available online that has been created about you.
This last type of offline data has been referred to as a digital shadow, rather than footprint, as you don't necessarily create it directly and it's pretty much unavoidable.
Your digital shadow can include medical records, travel itineraries, browsing history, security camera footage, bank records, info taken from smartphone apps and so on.
This information often stays siloed on the server that it's created on, but will likely be used (or made available to third parties) for the nefarious task of marketing.
And just because this information isn't available on the internet, doesn't mean that it isn't at risk of public exposure — look at the Anonymous hack on the PlayStation Network in 2011 for a high-profile example that involved the collection and distribution of 77 million accounts, including email addresses and hashed words.
Unfortunately, you have very little (if any) control over the size of your digital shadow and the companies storing this information are rarely held accountable if it's breached.
Your smartphone is just as guilty. It's common practice for many iOS apps (and probably Android apps, although they require permission at install) to upload your entire address book to their servers, meaning you can almost guarantee that your name, email address and/or phone number are sitting on a server somewhere, thanks to a friend installing a very dodgy app on their phone.
VentureBeat has a story on the practice that's worth reading.
There's clearly a heap of information available about you, both online and off, but why should we be fearful? A big concern is identity theft, where someone can gain enough information to convince, say, a financial institution that they're you and then get up to no good.
Even though it's usually phishing scams or data breaches of private servers that are responsible for this, you should still be aware that the small, seemingly disparate, pieces of information scattered around the net can be joined together to form a fairly comprehensive picture of your life.
Feeling suitably paranoid? Now is probably a good time to start thinking about the information that you do have control over.
An embarrassing past
Beyond identity theft, there are some genuine reasons to want to cover up your digital footprints, especially if they represent a part of your rebellious, naive youth that you no longer agree with. For example, you may be starting a new career as a public figure or even going on a blind date.
We're presuming you've already Googled your name in quotes and found something that you're not too happy about.
If it was beyond the first two pages of results, it's probably pretty safe from most eyes, but if not, or if you don't want to take the risk of there being someone determined to find some dirt, you'll want to take some action.
Unfortunately for you, you can't remove results from Google (or other search engines) directly. All you can do is make them less relevant and eventually, they'll drop off into the oblivion that lies beyond page 5.