When I was there even small store owners would try to size you up by the way you look and dress and gauge how much service they should provide. It is called "Qi Ruan Pa Ying" or "Bully the meek and be afraid of bigger bullies" as its closest translation

IIRC a while back you were stating that one should not be too friendly with supermarket workers, or even look kind of annoyed when asking for directions and so on, so as to avoid further questioning. Is the above related to this; and do you feel that this questioning always occurs in China to anyone deemed different?

Cheers
San Migs