A letter sent by the Italian arm of multinational company Boiron, threatening to sue an amateur blogger over remarks he made about homoeopathy, has sparked a strong internet reaction in defence of freedom of speech.

Samuele Riva posted two articles on his blog, blogzero.it, on 13 and 27 July,which included pictures of Boiron’s blockbuster homoeopathic product Oscillococcinum, marketed as a remedy against flu symptoms. The pictures were accompanied by captions, which joked about the total absence of any active molecules in homoeopathic preparations.

On 28 July Boiron fired off a letter to the internet provider, complaining that both the articles and the captions were “untrue and derogatory both of homeopathy and [the] company,” and responsible for tarnishing the company’s reputation and causing “serious …