Chinese media are full with articles looking into the bad habits of Chinese tourists abroad and much soul searching. For me, that is no surprise. They are behaving the same way as they do at home. Little or no respect for anything.
On social network sites and local forums, locals from Chiang Mai (Thailand) posted evidence of what they say are offensive acts by Chinese tourists:

A tendency to not flush the toilet.
Flouting traffic laws when driving, riding a bicycle, or parking their car.
Being loud – even in five-star hotels.
Littering, spitting, queue-jumping.
Allowing children to defecate in public pools.
Terrible English-language skills that lead to difficulties in communication.

That sounds oh so familiar! You don’t have to go to Thailand for this. Every day in Beijing. And, of being loud, Chinese people need to buy better mobiles or get their ears fixed: they shout when talking on the phone so anybody in a radius of 50 m can hear it. Worst are people from the South or even Hong Kong.
One reason why sometimes I avoid the crowds in China, unless I go there to watch the crowds rather than the venue.