The ASA has been stirring the pot with a number of food and drink advertisers of late, and this week there will be a few marketing men and women getting all hot under the collar over one of its latest decisions.

In July, after a hefty prod from Ofcom, the authority clamped down on broadcaster Channel 4 after a series of TV shows, including The Big Bang Theory, were found to have shown ads for beer, despite those shows being popular with children.

The ASA followed this up by asking whether enough was being done to prevent children from having access to age-restricted content on social media. This came after a report found the majority of young people are registering for sites such as Facebook and Twitter using a false age.

The watchdog’s latest decision takes another step into the murky world of social media, this time in the form of Unilever’s spicy Pot Noodle and the subject of sexism.

The ASA ruled, after 18 complaints, that an ad on the product’s Facebook site was “crass and degrading”. The ad in question featured a woman posing in her underwear alongside the snack, with a caption asking, ‘Which one gets you hotter?’

Yet two further online ads – a video in which a bus passenger enjoyed a pole dance by another ‘hottie’ before she turned into an ugly bloke, and another in which Pot Noodle lids were turned into a pair of cartoon breasts – were allowed, because they were judged only “puerile”.

This was despite the ASA agreeing that some viewers may have considered these ads to be “distasteful”.

The only difference between the three Pot Noodle ads appears to be that the offending image didn’t allow for a “humorous” twist such as the bus pole-dancer video, and that the cartoon version doesn’t really count because people don’t regard cartoons as offensive (try telling that to South Park).

Whatever you think of the ASA’s judgment, the case highlights the difficulty it faces in policing online content. It could be opening a massive can of worms if it continues down this road – and someone at the ASA is going to be spending an awful lot of time online looking at crass images.

Meanwhile, for advertisers, getting the tone and content of online campaigns right becomes ever harder.

Take an example from the US, where an ad featuring supermodel Bar Refaeli for web host GoDaddy.com showed the supermodel snogging a computer programmer next to the tagline ‘smart meets sexy’. The ad attracted more than 10,000 tweets – many of them claiming it objectified women (fewer objected to its stereotyping of IT nerds).

This sort of backlash will be on the mind of advertisers as they assess their strategies – as will the fact that it took just 18 people writing to the ASA to get the Pot Noodle ad canned.