The worst part about this is that people use Microsoft mail sofware like Outlook, exchange, etc to open and transfer these messages. It's so easy to spread trojans and other bugs in this stuff that people send the stuff on without any thought that they may contain malicious code. MS mail recognizes this stuff, and before you even know what's going on, the damage is done. Microsoft mail programs are obviously linked to other programs needed to perform their task, so the problem can be even worse. For example, if someone sends a text document, when you open it, it's gonna call up MS Word. MS word will run scrips, and the malicious code has just escaped detection of your virus scanner!
Non-microsoft E-mail programs just don't recognize embedded scripts in pictures, email, and other files that would make them malicious. It's also only Microsoft programs that recognize scripting embedded in other types of files, like pictures, documents, videos, sound bytes, and other material. I'm not running any microsoft mail program for this reason. Still, I don't want it if it's got a bug in it! So, if you're using a Microsoft product for E-mail, don't even THINK about sending this crap to me!