I agree that there is no privacy law violation, but it is a bit distasteful. We have some implicit standards in the society and it seems those are conveniently ignored at this point. There is some excuse given in the article in the form of "he probably gives out this number to people he does not wish to talk to", which I find a bit suspicious.

When I got letters to previous tenants at my current address I did not open them and share with everyone I met. I sent them to their new address.