iCloud locked iphone

the only way you'd ever find out the previous owner was if you bought it from the previous owner. there is not a way for you to look it up. in theory the phone was stolen from the previous owner, they wouldn't want to unlock it for you anyways

maybe look into reporting them on Facebook?

https://www.facebook.com/help/1295340050874305?helpref=faq_content

for future reference, you should always make sure an iPhone or an iPad powers on and displays the 'hello' screen in various languages. If it turns on directly to a Home Screen or doesn't power on at all.. walk away

glad to be of help.

If it helps further.. then this is the procedure one is supposed to do before selling an iPhone

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

oh, for sure.. if you are able to contact the seller, get a refund etc.. then that's the proper recourse.

I wouldn't come here saying you've been scammed if you're actually able to resolve this on your own....

edit:

I think I mis read your response.. you were suggesting that you could contact the real owner and give their phone back. Unfortunately this won't be possible

no, that info would likely be removed by the moderators.. Someone coming here looking for a lost phone and coming across this thread would be like a needle in a haystack I think.

If anything you could maybe call your local authorities and see if the phone should be turned over to them? Or if you pull the SIM card and it identifies the carrier, could maybe call them and check?