system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can hooliganism be orchestrated?

The news keeps talking about professional hooligans who are orchestrating violence at Euro 2016. I don't disbelieve it, but I just have no idea how it works. They get together and practice? They strategise beforehand?

There just seems to be a disconnect between the concept of hooliganism and any sort of planning. How does it work?
gpt
We live in an age where people with similar interests can very easily hook up using the virtual tools the internet provides. It's quite simple for someone that wants to engage in criminal activity to find others that do too. A quick chat with one hooligan will lead to others, and perhaps an in-person meeting, and suddenly you have a conspiracy. 

Throw in some access to funding, such as if there's organized crime that can profit or a political group that wants to make a statement or destabilize something, and even anarchists can get organized.