[FreeTheHostages]

"I think the best course of action would be to have a big police presence and be ready to swiftly round up (and lock up) any lawbreakers as they move into the streets to block them or take unlawful action on/in Metro, etc"

I agree. But the police could also put conditions on the permits.

[FreeTheHostages]

From their website:

We demand a change in the miserable conditions and exploitation enforced by these institutions and demand a world based on freedom and compassion. We demand:

That the World Bank and IMF be abolished! We don't want a seat at the table to discuss reform; they are not reformable.
An end to privatization and structural adjustment everywhere.
An end to all debt! From debt owed by developing countries to personal debt.
Housing and food for everyone.
Freedom for everyone - Immigrant Rights, Civil Liberties, Women's liberation.
An end to the racist prison industrial system.
An end to imperialism and terrorism by the US government and all states.
An end to the colonial status of DC and developing countries.
We are striving toward the abolition of capitalism! No longer should ones survival and access to human needs be determined by ones economic means