Freedom of speech thwarted on overpass

Holding 4-foot letters spelling out "NO WAR" and a picture of an Abu Ghraib prisoner, activists hit an overpass in the East Bay with their signs directed towards west bound traffic coming from the Dublin/Livermore area, a highly Republican area. Soon the activists received CHP officers coming to give them a warning, stating that if we posed a traffic hazzard they would come by and ask us to leave. From that first encounter to the second one, when we were asked to leave (from two different CHP officers) there was no change in the traffic conditions, in fact it was a pretty light day for traffic. Why the change of attitude?

We confronted the officers about their contradictory positions but according to one officer it was his decision to send us packing as he was responsible for this section of freeway. Huh? I asked him to show me the regulation that stipulated what constitutes a hazard and he said it was his call to make that decision, and he did. It was completely arbitrary.

Also, if signage is considered a hazard than why doesn't that apply to commerical advertising all over the freeways? All you have to do is look at that clog of freeway billboards in SF and on 880 to know that is a bunk argument.

Anyway, it sounds like somebody just did not like our message, and decided to silence us. The one officer did say that they recieved many phone calls in regard to this action.

Does anyone have any information about our legal rights to hold signage over freeways?