Without passing judgment of guilt or innocence on Bill Cosby, who faced and seemed to survive serious accusations decades ago only to see them suddenly resurface in recent weeks, I can confidently say that refusing to address the situation is the wrong move.
One basic tenet of modern reputation management is that when conversations about you are taking place widely on social media (and overflowing into traditional media), you should pump your own messages out there so that your side of the story is part of the conversation. Right now, Cosby's silence is allowing the crisis to grow and spiral more out of control.
Offering a meme-generator to remind audiences of his jovial public persona completely backfired, and issuing a statement from his lawyer doesn't seem to have quenched the negativity. As with Tiger Woods during his scandal, disengaging the news media is not the answer, nor is ignoring the loud social media chatter.
If he is innocent, Cosby needs to find a way to reclaim his reputation before his legacy is lost forever.