It appears that the court permitted service by Instagram on the basis that the defendant in the case is active on social media, but understood to be out of the country. 

The decision was made in the Intellectual Property Enterprise Court (IPEC) division of the High Court.

It will be interesting to see if this leads to an increase in cases where the court grants permission for the service of documents via social media platforms where it can be shown that the party being served uses that platform regularly. 

The courts took another step into the digital future this week when a judge accepted a court order served through Instagram

 https://www.newlawjournal.co.uk/content/instagram-first-paves-w