The protesters gathered in the main concourse of the station Tuesday where they held a noisy rally as hundreds of commuters rushed by.
A Metropolitan Transportation Authority spokeswoman says two summonses were issued and three people were arrested on charges of disorderly conduct.
Obama signed the National Defense Authorization Act into law on New Year's Eve. Civil rights groups have criticized provisions in the bill that they say seem to grant the military extraordinary powers to detain U.S. citizens indefinitely without trial.
The protesters held a series of actions Tuesday designed to call attention to the law.
You can watch YouTube videos of the protest taken by Melina Vargas:
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