A couple of examples in Europe. Different reasons.
Napoli fans release a statement saying they will remain silent when Milan travel to the Stadio Maradona on Sunday to protest against the increase in ticket prices and restrictions due to security reasons.
Bundesliga fans are planning a 12-minute silence across all league games this weekend to protest against the potential sale of TV rights.
In allusion to the effect of fans as the proverbial 12th member of the team, fan clubs and "ultras" from several of Germany's top clubs, notably supporters of Bayern Munich and Borussia Dortmund, announced on Friday Sportschau reports, that they will remain silent for the first 12 minutes of their teams' forthcoming games.