Be Careful What You Advertise
Be careful what you advertise – In the past, it was difficult to find information about people other than their phone numbers or address. Now, an increasing amount of personal information is available online, especially because people are creating personal web pages with information about themselves. When deciding how much information to reveal, realize that you are broadcasting it to the world. Supplying your email address may increase the amount of spam you receive (see Reducing Spam for more information). Providing details about your hobbies, your job, your family and friends, and your past may give attackers enough information to perform a successful social engineering attack (see Avoiding Social Engineering and Phishing Attacks for more information).
Realize that you can’t take it back – Once you publish something online, it is available to other people and to search engines. You can change or remove information after something has been published, but it is possible that someone has already seen the original version. Even if you try to remove the page(s) from the internet, someone may have saved a copy of the page or used excerpts in another source. Some search engines “cache” copies of web pages so that they open faster; these cached copies may be available after a web page has been deleted or altered. Some web browsers may also maintain a cache of the web pages a user has visited, so the original version may be stored in a temporary file on the user’s computer. Think about these implications before publishing information—once something is out there, you can’t guarantee that you can completely remove it.
by US-CERT
Authors: Mindi McDowell, Matt Lytle, Jason Rafail