Time was, there was no such thing as bad publicity. That time is past. Budweiser have been involuntarily product-placed in a Paramount Pictures film which grossed $25m last weekend and stars Denzel Washington, but they're still not happy. This might be because it stars Denzel Washington as an alcoholic pilot.

As his plane starts to fall apart at 30,000 feet, making a wayward journey to the ground via a church steeple, it's a bud that's shown in the cockpit. It's Budweiser's fault the steeple comes off.

"We would never condone the misuse of our products, and have a long history of promoting responsible drinking and preventing drunk driving," Budweiser's vice president Rob McCarthy said in a statement to the AP. "We have asked the studio to obscure the Budweiser trademark in current digital copies of the movie and on all subsequent adaptations of the film, including DVD, On Demand, streaming and additional prints not yet distributed to theaters."

But Budweizer can't really do anything about it. Trademark laws "don't exist to give companies the right to control and censor movies and TV shows that might happen to include real-world items," Daniel Nazer from Stanford Law School told the Associated Press.

So if a filmmaker decides on a storyline in which an entire village is murdered by Smints, Smints can't object. This is surely a worry for companies: negative publicity hurts sales. In most cases. But there is one case in which negative product placement has actually helped sales. This case is guns.

Hollywood does great product placement for guns. Whilst cigarettes are frequently edited out of the production process these days, guns still receive loving attention, even when held by the bad guys, or used to commit atrocities. Every James Bond has carried a Walther handgun. Dirty Harry called the .44 Magnum, "the most powerful handgun in the world." And this filters through to customers. The popularity of 9mms on the street has soared [2] since Hollywood started to suggest them as the "weapon of choice". (It was a 9 mm that was used in the killing of six Sikh worshippers in a Milwaukee temple.) Hardly great for their image - but you don't see the makers complaining.