Last time I visited your country I was greeted with graffiti written by locals saying "Tourists go home" Maybe Thailand are just returning the gesture ?
We also went on a train to San Jose for the day and that was an interesting place, very quiet and there wasn't as many people walking around the downtown, but I have to be honest it felt a lot safer there to me, we didn't venture into Oakland although we wanted to go over the bridge, the Media possibly played its part in stopping us going there.