The ads, starring comedians David Mitchell and Robert Webb, stars of Peep Show, as a PC and a Mac respectively. The ads have been plastered just about everywhere and you can't really avoid them when you are in the UK. The authority received 14 complaints from the public.

Some complaints centred on whether it was misleading and irresponsible to assert that Mac owners wouldn't have to "worry about the viruses and spyware that PCs do". Other complaints focused on claims that Macs crashed far less than PCs, and implied that all PCs, regardless of the software or operating system they used, were more likely to crash than Macs.

Apple said the claims were based on PCs that ran Microsoft Windows, which it believed were more vulnerable to crashing, would contract more viruses and would need to be restarted more frequently than Macs. It said the ads were targeted at the home consumer, not the technology professional. The iPod makers said that almost 97 per cent of home PCs were used for non-commercial purposes and ran a version of Microsoft Windows; it said it believed the claims were accurate for the ads target audience.

The ASA did not uphold any of the complaints lodged.

"The ads did not misleadingly imply all PCs, regardless of software or system, were vulnerable to crashing and viruses," the ASA said in an adjudication statement.

"We considered that people would understand that to mean viruses that infected Windows-based PCs would not infect Macs and that Macs were less likely to be infected by viruses than those PCs; not that Macs would never be infected by viruses and did not require virus protection," the authority said. "We concluded therefore that the ad was not irresponsible or likely to mislead."

Here is the adjudication.