Starbucks asks a customer’s name when he or she orders a drink, and writes it on the cup. In this particular case, when the customer stammered on his name the barista allegedly wrote RRR…ichard on the cup.

The customer found this extremely offensive and humiliating. He complained on the Starbucks Facebook page. The barista was suspended pending disciplinary action, and Starbucks apologised to the customer.
Disability Rights UK said that if he wished to pursue a legal case it would be happy to put him in contact with a suitable lawyer.
Reported in the Mirror 20/1/17, Daily Mail 20/1/17.
My comment
If the reports are correct, this is likely to be harassment under the Equality Act 2010, and quite possibly direct discrimination.
Also Starbucks’ system of having to say your name when ordering can be a problem generally for people who stammer, and may itself be indirect discrimination or a breach of the reasonable adjustment duty under the Equality Act.