While we are on the subject of conducting forensic investigations by local (usually small) law enforcement units, here is another story from Connecticut.

A Norwich, Conn. substitute teacher was convicted on charges that she endangered her pupils when the students saw pornographic pop-ups that appeared on her schoolroom computer. While prosecutors maintained that the teacher visited pornographic Web sites while at work and wondered why she didn’t just turn off the computer, a forensics expert testified that an innocent hairstyling Web site that the teacher had visited installed spyware on her computer and led to the pop-up pornographic ads, according to an article in the Norwich Bulletin. Moreover, police investigators apparently did little forensics investigation on the computer and the school did not maintain the security software on the systems that could have prevented the spyware from installing, according to reports on the case.

Moral of the story - in the interest of justice, especially when life or liberty is at stake, insist that proper forensic investigations take place on the computer in question.

steganography (n.) The practice of hiding messages, often by writing them in places where they may not be found. Often (wrongly) used to mean the same as cryptography which relates to encoded messages.

Why Use Steganography?

Unlike encryption, steganography (or stego for short) is useful to "hide" data in a way that a third party would not know of its existence and hence would not try to break its encryption or force the encryption key from its owner.

There are many uses for steganography, especially in the information security and privacy field. You may want to exchange sensitive information like passwords or shared secrets over an insecure transmission protocol, such as email or ftp. You can embed secret files that should be available to selected audience. You can embed copyright information into digital files and control distribution of content. You can store your own sensitive information in an image, upload it to a flickr, and have the information available anywhere in the world (subject to decryption, of course.)

Stego Tools

There are a variety of tools that allows steganography. Here  is a sample of few.
- Hide in Picture (Win) - allows you to embed a file into a GIF or BMP image and lets you set a password to retrieve the hidden file.
- wbStego (Win) - allows you to embed files into PDF, HTML, or bitmaps.
- mp3Stego (Win) - allows you to embed files into MP3s
- PictEncrypt (Mac) - adds text to GIF, JPEG, TIFF, PNG, and MacPICT images.

More tools and tutorials.