The coffee chain Starbucks got a lot more than it bargained for following the launch of its new Twitter campaign.
The SpreadTheCheer hashtag was quickly besieged by disgruntled protestors complaining about the firm's tax status.
In an online PR campaign gone awry, the Twitter feed was then allowed to be broadcast unchecked onto a big screen at the Natural History Museum - as part of Starbucks' sponsorship of the ice rink located at the museum over Christmas.
Following the release of figures which showed the coffee chain had only paid £8.6m in corporation tax since launching in Britain, the firm has been under a lot of scrutiny: and Twitter users were quick to use the new hashtag campaign to flood the firm with their thoughts on the matter.
One user poked fun at the coffee giant in a tweet which read: "Tax paid: £8.6m. Additional tax paid to improve public image: £20m. Posting live tweets to a big screen: priceless."
Others were not as witty in their views, choosing instead to use profanity to get the message across.
A spokesman from the National History Museum apologised for the gaffe, blaming a crash that left the moderation filter down - resulting in the broadcast of two comments that included swear words.
A Starbucks spokesman also blamed the incident on a temporary malfunction of the content filtering system and apologised to visitors: "who may have been offended by inappropriate messages displayed on the Twitter wall screen."
Over the last year, many firms have taken to using Twitter as part of a wider Internet marketing strategy, with social media marketing across a multitude of platforms such as the micro-blogging site, playing a significant part in that.
Unfortunately for some, they have then fallen foul to the fact that people responding to the tweets can say whatever they want - if the platform is left unchecked.
The upmarket store, Waitrose, found itself in a muddle after Twitter users posted messages on #WaitroseReasons poking fun of the posh image of the brand.
Fastfood chain McDonalds also found its hashtag campaign #McDStories became an arena for customers and ex-staff to vent frustation about the chain, as opposed to sharing the intended heart-warming tales of Happy Meals.