Ermine or vermin?

I was rather taken aback by this ghastly infestation on some hawthorn trees.....thousands of creepy caterpillars suspended in a disgusting sticky web have destroyed all the foliage. It's like something out of the "Alien" movies.
Turns out it's this: http://www.dailymail.co.uk/news/article-2195935/The-hungry-caterpillars-Thousands-moth-larvae-weave-giant-web-shrubbery-protect-importantly-food-predators.html