I would say that the Pentagon Papers case of 1971 - in which the government tried to block the The New York Times and The Washington Post that they obtained from a secret study of how we got involved in the war in Vietnam - that is probably the most important case.

The government would be able to go to court with respect to newspaper articles, broadcast pieces and the like that they thought were bad or harmful or even against the government and try to block them.

My role in it was not as central as it was in some of the later cases considering I was younger then and I was playing a role of co-counsel on the case.

Floyd Abrams Quotes