It's not your traditional shopping, but it's shopping nonetheless.
These days, some are using what's called 'marketplace' apps like LetGo and Offer Up.
"Apparently on these apps, you can offer to sell or buy stuff on these apps. It's semi anonymous and you meet up with people to make the transaction at a location you agree upon," said Sgt. Richard Helterline, Syracuse Police Spokesman.
In Syracuse, these apps have been used to carry out robberies. There have been three since the start of December.
"The person that was selling their product was robbed of their product by the suspect. The suspect had a gun in all these circumstances," said Helterline.
Luckily, no one was seriously injured but they were definitely shaken up.
"They were surprised...I'm sure scared. They weren't expecting that. I'm sure they probably had success in the past and this surprised them. It wasn't planned, but we just want people to think ahead. You've got to think for your safety," said Helterline.
To avoid anything sketchy, officers have some tips for safe transactions, like meeting outside the police department.
"Tell them that's where you want to meet," said Helterline. "I would hope that if a robbery happens, they wouldn't do it in front of the police department. Bring a friend with you. Don't be alone. Don't go to places that you don't know. Don't have people come to your house. Don't go to someone's house."
Police want to stress caution, because this is the holiday season. Your safety senses should be heightened.
"If we get the word out to prevent some of these things from happening and hopefully maybe prevent tragedy ... We're not telling you not to use them, but just be very cautious and be aware of what you're doing," said Helterline.