EU migrants have a unfortunate habit of assaulting truck drivers, setting up baracades (like in the vid) and Doing whatever they can to get inside the Truck, sometimes they try to break the lock sometimes they rip open the canvasing with knives The end goal is either to steal the goods in the truck or more commonly to hide inside the truck while it crosses over to the UK
http://imgur.com/gallery/zkafo
https://www.youtube.com/watch?v=382njADcWvE