PepsiCo have had yet another PR nightmare, this time from its crisp brand Walkers. The British snack food manufacturer saw its Champions League Twitter campaign hijacked within hours of its launch.

The campaign, which was giving fans the chance to win tickets to next week’s Champions League final in Cardiff, asked Twitter users to respond to a Tweet from the Walkers Crisps account with a selfie and the #WalkersWave hashtag. This selfie was then incorporated into a personalised video, featuring the face of Walkers Gary Lineker, and automatically Tweeted out.

This, of course, inevitably backfired as Twitter users began sending in pictures of range of infamous serial killers and disgraced celebrities, including Fred West, Rolf Harris, Jimmy Saville, and many more.

“Had an unusual day in some very strange company. Im sure well wave goodbye to them all by tomorrow,” said Gary Lineker on Twitter.

Walkers was forced to pull the campaign from Twitter and delete the undesirable replies that it received, saying “We recognise people were offended by irresponsible and offensive posts by individuals, and we apologise. We are equally upset and have shut down all activity.” However, the remains of the campaign can still be seen floating all over Twitter.

The problem with the campaign stemmed from the lack of human verification of the pictures being sent in, and the marketers really should’ve known better than to think using an automated system would’ve gone off without a hitch.

“The recent Walkers campaign is a big lesson for all marketers. It is an unfortunate turn for the brand but not a completely unexpected one,” said Marta Safin, social account director at mobile-first agency Fetch. “Marketers have to be very careful to not be seduced by automation as it can easily get out of hand. We need to embrace technology and innovation but remember that it cannot replace the human element. Walkers’ troubles could have been avoided by having a team of community managers keeping a close eye on the content being submitted.

“The campaign was a great idea but the execution missed a very important step of quality control. Social media is ‘social’ and by its nature, is all about human interactions, however, brands relying solely on automation are putting themselves in a vulnerable position.”

The campaign is another example of a PepsiCo brand failing on a PR front, and comes just a month after its flagship brand Pepsi was forced to pull its controversial TV ad featuring Kendall Jenner.