Petitioning your government is not extortion anymore than striking workers demanding a pay increase or safe working conditions, etc.
Its not that they are doing it, its how they are doing it. In this case preventing citizens from going about their lawful businesses, breaking noise ordinances, repeated harassment of innocents is not protest.
Remember strikes happen on private property, only impede access to said property, and they can't outright stop traffic in and out, just slow it. So the protesters have well beyond legal limits.