A new study of more than 1,000 fans says cocaine use can make them more abusive and violent towards rival supporters.
The "Created by the Poor, Stolen By the Rich" banner from Tunisian Club Africain has come to symbolise the fight against big money in football.
Some old-school hoolies have quit fighting on the terraces to battle their hardcore addictions.
This weekend, during a clash between Everton and Millwall fans, one fan had his face sliced from mouth to ear.
Toronto FC supporter group Inebriatti learned this lesson the hard way, leading to their status being revoked by the Major League Soccer club.
“He seems to be connected in almost every European country through his fighting and hooligan activities.”
Photographer Pavel Volkov documents from the heart of his motherland.
War on the terraces? Jamie Carragher spitting in someone's face? It’s been a great weekend to be a football fan.
For better or worse, unlike other countries the UK has a long history of "hoolie literature". These guys want to spread the joy.
Flyvende rotter, brændende sæder og invasion af banen. Det går ikke stille for sig, når de voldelige fraktioner af FCK's og Brøndbys fans tørner sammen på stadion.
"When I saw some friends collecting rubbish bins to set on fire, I knew it was going to be a long day."