A suspicious letter containing an unidentified white powder sparked a massive security alert at CBS studios in Hollywood Wednesday afternoon.

TMZ reports that police were called in after the letter, which was addressed to 'Dancing With the Stars,' was discovered in the mailroom of CBS Television City around 2PM PT.

LAPD spokesman Richard French told the Associated Press that no one was exposed to the white powder and no injury was reported.

A hazardous materials team gathered and tested the powder before declaring it harmless.

After a threatening letter arrived at the studio for 'The Late Late Show' (Weeknights, 12:37AM ET on CBS) with white powder in it, which was ultimately declared harmless, the show went on and Lewis Black came on as Craig Ferguson's guest.

"It's always really a joy to drive up for a big night on television and see cops everywhere," Black said of the state in the studio when he arrived. When Ferguson asked if he'd ever gotten any threats like that, Black insisted, "I have no affect on the world, so they don't care. They don't even notice me."

It sounded like Black would love the validation of a threatening letter with some mysterious white powder in it, though we're certainly not endorsing anyone sending him anything. As for the powder, it turned out to just be corn starch, so maybe Ferguson simply had an angry fan who liked to cook.

(S02E11) I still get the feeling that they swapped a couple of episodes around, but things definitely feel like they're finally back on track. The opening scene had me questioning my sanity just a bit, but I enjoyed the writers joke on everyone who saw the preview. Considering SciFi's generally misleading preview bits, it was a nice to see the show take advantage of it.

Keith Olbermann sent out a 'Thank You' to Homeland Security agents during his newscast last night for catching the guy who kept sending him white powder in the mail. Police say he also sent letters with white powder in them to David Letterman, Jay Leno and Jon Stewart, as well as Speaker of the House Nancy Pelosi. FBI agents arrested Chad Conrad Castagana, 39, in Los Angeles over the weekend after he mailed another letter to Olbermann with white powder inside. Castagana reportedly said he sent the white powder and threatening letters to high-profile people because of their "liberal policies". Luckily, the white powder was not anthrax... unlike the letters send to Congress and news anchors in 2001, which remain unsolved.

Last night, Olbermann also reprimanded the New York Post for reporting on the letters on its Page Six gossip section. He said that the Post effectively confirmed he received the letter, which encouraged Castagana to send more.

Are the bands Anthrax, Skid Row and Biohazard really classic rock? I guess they're close enough because artists from each of those bands (Scott Ian, Sebastian Bach and Evan Seinfield, respectively) will be teaming up with Ted Nugent and Jason Bonham (son of Led Zeppelin drummer John Bonham) for a new VH1 reality series called SuperGroup. The show will chronicle the five rockers as they prepare for a concert in Los Angeles. The show is currently in production, and an airdate has been set for May 18. In the meantime, I'll be trying to find a wormhole in the space-time continuum so I can help these rockers travel back to 1989 when people might have actually been excited about seeing them play together.