Buying a second hand iPad what do I need to be aware of and how do I know if it's been stolen or locked?

The serial number won't help. Unless you can actually meet the seller and verify that Activation Lock is off and that the phone works, don't buy it. The other thing to be aware of is some people will sell an iOS device that works, then report it stolen and blacklisted so they can file an insurance claim. It is very risky buying any used iPhone or iPad.

The only time I’d risk buying a second hand iPad is if the place is willing to stand behind it...some place like apple’s refurbished division or a reputable place with a good return policy.

Some info here: what-to-do-when-buying-second-hand-ipad.html

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