Viruses are invented by these people who need money and anything could be considered a virus depending how it is distributed to you. Most know what the cookies are that save in your web browser cache while browsing the Internet until they either expire or you clear them out yourself. When you go to igoogle and save it as your home page, you are voluntarily installing cookies into your computer. The same goes for plugins that are firefox, Internet Explorer and chrome, you are doing it knowingly. Than you have the ones that do it in a sneakly way and reel in a few suckers.
With the huge Harry Potter and the Half Blood Prince, you probably know people are searching for leaked copies of it. This gives the trolls the opportunity to say they have it and than seventy-five percent of the time somebody goes back a second time just to see. Great idea when you are running advertisements. A few might say they have the video but your missing a codec to be able to watch it.
If it is a legitimate video or audio codec, there isn't much need for a codec that no other site has ever asked you for before, especially if you have to download an unknown executable.
Earlier somebody comment spammed my post "Virus Alert - Harry potter and the Half Blood Prince Streaming Video". Don't try this at home on windows unless you know what you are doing. I checked out the site and every single link tries to download the so called video codec they are saying you need. When you hoover your mouse over the link, look dow in your bottom left and you can see the link name. The site only had links pointing to the same domain name.
I am well aware of my ability to piss people off especially when they piss me off first. Somebody kept spamming my clips in clipmarks and the third time I was really annoyed, because when somebody runs around and drops their web link all over the place it brings their site to the top of the search engines, so annoying when it is for something that doesn't really exist. I went over to his clip and pretty much left a truck driver comment. Than he did it one more time, so I spammed every clip with, "Beware this site has a virus". That brings your site down in the search engines, and pretty fast. Well I am sad to say I can no longer leave comments on his clips anymore :O. Than later that night I found the block one and just use that. Because I check my email multiple times a day and set every important site to notfy me with comments, spam usually doesn't leave trails on any of my sites for very long.
This must make him really really mad because I'm watching you!