Women on the Upper East Side told us it's something most of them didn't think about until now.
In each of the attacks, the man was lurking in the building's vestibule or in the hallway.
All of the victims were cornered in their lobbies or just outside their apartments, where the suspect was waiting to push his way inside.
Police released surveillance video taken moments after the latest robbery. In the suspect's pockets - a watch, cash and the victim's i-Pod.
The Upper East Side bandit struck first last Wednesday on East 79th Street at 12:40 in the afternoon.
He struck again on East 69th Street less than three hours later.
Later that night, he struck again on East 93rd.
He struck twice on Thanksgiving, once at 10:14 in the morning on East 89th Street and again that afternoon on East 78th.
He is described as an African American with a medium to dark complexion. He's believed to be in his thirties, just over six-feet tall, weighing just over 200 pounds.
According to police, he is clean-shaven and bald.
He was last seen wearing a waist length black leather jacket, black sweater, dark pants and black sneakers.