It has been questioned if ad agencies and web publishers have a legal responsibility to ensure that their advertisers are legitimate and acting within the law. Online classified website Craigslist was accused by a sheriff in Chicago to be soliciting prostitution by allowing for females to post ads for sexual services on their network. The judge ruling in the matter dismissed the case and states in his 20 page legal discourse that:
Intermediaries are not culpable for 'aiding and abetting' their customers who misuse their services to commit unlawful acts.This is a major win for online ad publishers. It establishes precedence that web publishers aren't liable for potential wrongdoings of their clients products or services.
It's not surprising, Newspapers, after all, have always retained a degree of isolation. It would seem bizarre to hold the LA Times responsible for an advertisement of an illegal product or service. Can you imagine blaming the newspaper when a private party advertises and sell stolen goods, or an unlicensed practitioner performing their services, or for that matter any false advertisement? Unless the publishing company is somehow further involved in selling or delivering the service, or violates a trademark, the act of displaying the ad does not make them responsible for potential illegal activity that subsequently occurs. The same rationale should be applied to the online world.
Related to this legal precedence is the 1st Amendment, freedom of speech, which allows most publications to state or show any content they desire. Publishers generally apply editorial policies that are in line with what their audience find acceptable. At my company, RelevantAds, we take significant efforts to ensure the validity and accuracy of the businesses we advertise for; but it would be nearly impossible for us to perform diligence on our clients are ensure that they are procuring products or services in a legal manner.