Galatasaray fans really like their flares. They generally just like fire, and sometimes that can be cool.
When they are throwing flares on the pitch, at fans and lighting the stadium on fire, it is not cool.
That is what happened in the Champions League on Tuesday. Fans began throwing flares early in the match and the referee had to stop the action until they could be cleared. Then, Galatasaray fans threw flares into the Borussia Dortmund section and they burned in the seats and the match was delayed again.
It's almost like Galatasaray fans want to see how many things they have to light on fire before they get their club banned from European competition.