It is quite obvious that there is a large section of the population that misunderstands the First Amendment, and has no concept of property rights. While the First Amendment does protect you from government persecution, you are not guaranteed that right when on private property. Two peaceniks who were asked to either leave a shopping mall, or remove their T-shirts that had anti-war messages written on them found out the hard way.

Just because a business opens it's doors to the public, does not make it public property. Business and property owners, just like homeowners, have the right to ask people to leave. When you don't leave, you're trespassing, which is presumably what these stubborn people were charged with.

UPDATE: I noticed today (03/05) that ABC News (radio) had added some twists to the story. Rather than admit that a shopping mall is private property, ABC called it a 'public mall'. They also neglected to mention that the man arrested was offered several chances to leave the property, prior to being arrested for trespassing.