The Times, The Telegraph, The Sun and Transport Secretary Chris Grayling have already labelled any culprits as 'eco-warriors' and that was even before these two were arrested and then released. https://www.desmog.co.uk/2018/12/21/comment-why-it-s-too-soo...
What is the aim of any protest? Is it to get publicity or to make an actual impact? Might environmental activists be fed up with the limited effect getting in the news brings, and like the yellow vests over the channel, prefer actual effects? "The revolution will not be televised" for the 21st century.
Id like that to be the case as it's more interesting, but in this case I suspect a couple of pranksters having a laugh amongst themselves.