Section 8 is a federal voucher program designed to help low income families afford decent housing. You have your own reasons for wanting to prevent this from happening, but be warned: it is discriminatory, thus illegal, to prevent section 8 housing without a cause. There are resources available to you if there is a real reason you want to prevent or reverse a Section 8 housing in your neighborhood.
Check for restrictions or rules regarding your current living situation. If you live in a condo or are part of a homeowners association, for example, you may be subject to rules that pertain to the total number of rentals allowed.
Talk to the board that controls the bylaws associated with your neighborhood. You can change whether you want to allow renting in your neighborhood, but you cannot single out section 8 housing as this would be discrimination. This option may be difficult or take significantly more time if you already have people renting out the space.
Contact the housing authority in your city to find out the requirement and qualifications for Section 8 housing. You can report the Section 8 tenants to the housing authority if you notice they are not following the rules.
File a complaint with the housing authority, but only if you have a valid complaint.
If the Section 8 tenant are being a nuisance or otherwise creating an unpleasant atmosphere you can talk to a lawyer about pressing charges to get the problem solved.