It is important to protect your system through antivirus software and it doesn't have to cost you a thing. Many reputable sites have popped up over the last few years with free antivirus to download offers. These freeware services are actually as good as anything you would pay for in the store. They work great and by downloading them you are often helping to promote an up and coming software developer.
If you are a fan of Linux it only make sense that you would be a fan of free to use antivirus software. Why give your money to mass conglomerates who overcharge for their antivirus software, when you can get quality software for free to do the same job?
Free antivirus software is an excellent way to promote a new software engineer, get something for free that should come standard, and show expensive software companies that their are alternatives to their product.