Another case of habituation.
Fed by Indians, Monkeys Overwhelm Delhi - NYTimes.com:
"The first interloper stepped in front of her on the sidewalk and silently held up his hand. The second appeared behind her and beckoned for her bag. Maeve O’Connor was trapped. Resistance would have been dangerous, so Ms. O’Connor handed it over. The two then sauntered arrogantly away. The whole encounter lasted no more than 15 seconds — just one more coordinated mugging by rhesus monkeys. . . some residents are getting a bigger monkey, a langur, to urinate around their homes."