Chris Brown's alleged assault on girfriend Rihanna has cost him deals with Wrigley's and the California Milk Processor Board's "Got Milk?" campaign, but the embattled singer is still up for a Nickelodeon Kid's Choice Award, as parent company Viacom refuses to take Brown off of its fan ballot.

A petition posted by the group Twittermoms decrying Viacom's decision to keep Brown on the ballot had already gathered more than 1,500 signatures as of Tuesday morning.

RELATED: Click here for the latest developments in the Chris Brown scandal.

"My kids will not be watching Nick anymore," one post read.

"[Brown] is not a role model," another read, "Shame on you."

LINK: Click here to view the Twittermoms petition.

So why is Viacom, which has said it will "let the kids decide" whether Brown wins an award or not, resisting any action against Brown?

Over the years, some of the world's most famous celebrities, including Madonna, Michael Phelps, Kobe Bryant and Michael Jackson - even the Olsen Twins - have lost lucrative product deals in the wake of personal controversy.

Click here to see how five major celebrity scandals played out in corporate boardrooms, and see how quickly some of the world's biggest companies have distanced themselves from their biggest names.