Year: 2000

Predicted outcome: Not applicable

Actual outcome: Over 50 million computers infected; over $5.5 billion in damages

The ILOVEYOU virus was a . Similar to other e-mail worms, the virus required that users run the executable file (written in Visual Basic Scripting, or VBS). To induce victims to do so, the worm disguised itself as a text file by putting .TXT into its name; when people saw that the file was called "LOVE-LETTER-FOR-YOU.TXT.vbs," they thought they were opening a harmless text file.

Once the victim opened the file, the worm would send copies of the e-mail to the first 50 contacts in the user's Windows Address Book, and then make changes to the system (it would , including all .JPG and .DOC files, with copies of itself).