[tomtang0514]

I think that's exactly the case. From the picture there seems to be a mechanical password lock on the umbrellas. I guess how it works is: You can the QR code -> pay thru app -> received password, input the password on umbrella -> unlock umbrella. But since it's mechanical lock, I assume the password doesn't change every time. Then whoever returns the umbrella knows the password and can just take it away directly. The company can't prove they steal it.

[Bakary]

This is exactly what happened to a lot of ofo bikes. They then scratch off the serial number and qr code so that no one else can use it.