Religion
Almost equally insensitive would be to disregard certain religious precepts.
Buddhism plays an essential part in the lives of most Thais, and Buddhist monuments should be treated with respect – which basically means wearing long trousers or knee-length skirts, covering your arms and removing your shoes whenever you visit one.
All Buddha images are sacred, however small, tacky or ruined, and should never be used as a backdrop for a portrait photo, clambered over, placed in a position of inferiority or treated in any manner that could be construed as disrespectful. In an attempt to prevent foreigners from committing any kind of transgression the government requires a special licence for all Buddha statues exported from the country. With the above in mind, there is however no need to worry about taking photos of Buddha images or temples, inside and out. So long as it's tasteful in their eyes.