The safe way to market your products is through celebrity endorsements. This is when Brands sign up a celebrity representative who will use/wear the products and be involved in the Advertising and Media Campaigns. If a Celebrity does something negative you can always end the relationship. Usually just the announcement of severing ties is enough to mend the damage to the association with your brand. On occasion this will backfire. Kellogs recently severed ties with Michael Phelps over the photo of him using marijuana where quite a few people vocally called for boycotts of Kellogs products. But usually it is just the celebrity who becomes damaged.
But when a Brand actually develops a product with a Celebrity such as the Air Jordan sneaker a brand risks being left with a ton of inventory and a waste of resources developing the product that could of been used elsewhere.
Sometimes the celebrity can actually do nothing illegal yet a Brand can get left holding the bag. A great example is Nike just launched a Men's Sneaker co-developed with Kanye West who is a music entertainer in the Hip Hop Genre. The same week of the launch unwittingly to Nike, South Park a cartoon on Comedy Central had Kanye as the focus of an episode ridiculing him for not being heterosexual, for being vain and self focused, not very bright and that he has sex with fish.
It doesn't take everyone to watch the episode but word of mouth could damage the celebrity brand. Brand's beware!