"Is that a crime?"
Yes Kebede, in Californicate it is a crime. Of course they haven't really codified it into law yet, but the De Facto reality is you are just as likely to be arrested for flying an American flag as you are for selling drugs.
There is a strong anti American culture in CA, and it is promoted by corrupt politicians, low life bureaucrats, the media, and liberals in general. Ask any CA veteran.
You can sometimes find articles in the newspapers, proclaiming those who fly the flag are gang or militia members. been there.
There is a lot of blame to lay on California, but this episode is not one of them - this clearly has its roots in the multicultural, upside-down world of academia and could have happened at almost ANY university throughout the country today. And you shouldn't paint San Diego withn that same broad "anti-American culture" brush that may apply elsewhere in the state.