They can, but they rarely if ever got it, at least in the 28 years I was there. It especially bothered a lot of fans when they requested viewing of the Steelers vs Browns games, since that was 90% of the viewer fan base. I left in 2014 so I don't know if things have changed much. The NFL made some changes to blackout rules in the past few years, so maybe they softened the viewing contracts as well...although I believe, since they were in Buffalo's market, the Bills would have to agree.