Customers at restaurants on Michigan, Fairbanks, Wabash and Ontario have been robbed in the last four days.
Police say a group of young men approach diners to say that they are raising money for a basketball team. The thieves put a flyer on top of the customers' cell phones. The men pick up the flyer and the cell phone as they leave.
"I was eating by myself tonight and scrolling on the phone and didn't even think that someone might come and swipe it," diner Todd Ganz said.
The team of thieves is operating in three different areas, police say: in the 400-block of East Ontario, the 600-block of North Fairbanks, and in the Loop along Michigan Avenue and the 100-block of North Wabash.
"My grandma told me a little bit about it. She saw it happen to somebody and she warned me about it," diner Krystal VanWoerden said.
Police say the group consists of three or four males, 14-25 years old, traveling in a tan, hardtop sedan.
Wednesday night at a Streeterville Starbucks, the thief came in and asked for water, according to employees. He then snatched a phone from a table where 3 customers were sitting, they said.
"You wouldn't put $300 on the table and not pay attention to it - so your cell phone has value, they recognize the value," Chicago police Sergeant Lawrence Coleman said. "They know they can turn these cell phones over to a pawn shop and get a couple hundred bucks."
A similar theft ring targeted diners last year.
"We think it's either part of that group or a whole new group altogether who are copycatting the same type of activity," Coleman said.
Police warn diners to take precautions.
"Usually, I try to keep it on the inside of the table so it's not too exposed or keep it in my sight the whole time," diner Ryan Garcia said.
Police recommend that If you are confronted to remain calm . Remember any unique physical characteristics the suspect may have, like tattoos or scars. Never pursue a suspect and after calling 911, remain at the scene if possible