[Anechoic]

"Get the music blaring [...]"

This piece of advice will get people fined (and possibly arrested) for violating noise ordinances in many municipalities. You're better off marching silently.

[colonelxc]

The police were already announcing that people marching through the streets and blocking traffic were going to be arrested anyway, so it's not like marching silently would save them from the threat of arrest.

[Symmetry]

They're already violating a lot of ordinances - a few more won't matter much.

[dmix]

I imagine thats how tons of kids justified breaking into stores during the Vancouver hockey riots.

[nerfhammer]

Those would be felonies though

[jfoster]

If you're particularly worried about getting fined/arrested, then blocking traffic is also going to be a problem.