What are the dangers of smartphone buyback service?

Question

Analyst estimate that 257 million used smartphone will be sold  in 2018 - a huge increase compared to 53 million sold in 2013.

What will happen with the personal information stored on those resold smartphones? Will the former user factory reset the phone? Or the buyback company will handle this? And is it enough? Are there other dangers?

Answer 1

Generally the company is obligated to purge customer data on the devices that they purchase, however it's best to wipe the information on your device as best you can because their employees may breach company policy and view or use the data.