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I found a vodafone samsung s8, but it is password protected and I can't access it to call contacts. I live in the United States (Washington, D.C.). There is a sticker on the back with IMEI number and S/N. Anyway I can give that to you to find the owner and let them know I have it to give back to them?
Is it definitely Vodafone UK as many countries use the Vodafone name but are not linked.
Due to Data Protection Acts the Networks won't be able to access owners details.
With the s8 a user can add emergency contact via the phone app icon on the lockscreen. If it's there then long hold and swipe it up.
Or try holding the dedicated Bixby button and ask it to call home. That's if the owner hasn't already blocked it.
The owner can also use findmyiphone to locate it and ring it etc.
Other than that it won't accept another sim card due to its security protocols and Samsung won't help too.
Hand it to the authorities as a last resort.