One example: the Burger King cheeseburger that Robert Downey famously downed in Ironman. That baby won enormous criticism from parent groups as well, including the Campaign for a Commercial-Free Childhood. They accused the ad of promoting obesity in kids and recommended it, and others of its kind, be banished forever.
Other groups have called for advisories posted at the beginning and end of the film while watchdog group Consumer Alert petitioned the FCC to require advertisers to disclose all product placement ads on TV. In one YouTube interview, legendary filmmaker David Lynch was asked for his opinion on product placement. His response was a series of expletives I won't repeat here.
Naturally, advertisers disagree. An editorial this spring in Advertising Age claimed that people don't notice or don't mind the labels, logos, packages and mention of brands scattered throughout the screen. Besides, they argue, how else can advertisers effectively reach a captive consumer? While Americans spend more time watching television than anything besides sleep and work, increasingly few stick around during commercials.