The thieves snatch victims' wallets, credit cards and cash before going on a spending spree, usually buying gift cards.
In some cases, they've even been able to take money from the victims' bank accounts.
They have struck at least 11 times, at all hours of the morning and night across the city.
Authorities were about to obtain surveillance photos of two suspects using a victim's credit card.
Anyone with information in regards to any of these grand larcenies is asked to call the NYPD's Crime Stoppers Hotline at 800-577-TIPS.