What happened at the weekend with anti-migrant protests in the south of England?Early on Saturday morning, a crowd of up to 500 black-clad, masked men arrived in the Kent town of Dover and blocked the main roads leading to its port. It is the main arrival point for illegal migrants who make the crossing to Britain from France in small boats.The protesters chanted the well-worn mantra of the UK’s anti-immigration movement: “Stop the boats.” For several hours until noon they succeeded in their aim, albeit the boats they stopped were mostly passenger ferries going in the other direction.The non-violent protest was highly organised and caught police off guard. The organisers claimed to have lawyers ready to speak over the phone to police on the ground, while the masked men, who were accompanied by their own contingent of social media streamers, carried paperwork spelling out their legal rights.Protesters at Dover Priory train station after black-clad and masked demonstrators blocked roads in Dover during a protest. Photograph: Oscar Rihll/PA Wire Police officers at the scene near Eastney Beach, Portsmouth, where hundreds of protesters gathered after a small boat thought to be containing asylum seekers landed. Photograph: Jamie Lashmar/PA Wire