Marks and Spencer have succeeded in requesting that an ice cream parlour rename their "Percy Pig" flavoured ice cream.
Marks and Spencer owns trade marks for the mark PERCY PIG, which M&S refer to as one of their "hero" products. They became aware that Fabio's Gelato were selling an ice cream flavour entitled "Percy Pig" ice cream and wrote a letter to the the owner to request that they ceased use of the mark in this manner, on the basis that they could risk the loss of their trade marks if they do not take steps to prevent unauthorised use by third parties. Furthermore, allowing such unauthorised use could run the risk that customers will no longer be confident that Percy Pig branded goods originate from M&S.
The "polite and fair" letter had the desired effect and the ice cream parlour owner agreed to change the name. In a social media savvy world, where legal letters can often end up being posted online (as was the case here), it is worth giving consideration to tailoring the tone you adopt to the recipient when enforcing your trade marks - M&S got the outcome they wanted and good publicity to boot.