The USPTO will no longer include the inventor's mailing address on unassigned patents and published applications because of privacy concerns. However, correspondence information will continue to be available in Public PAIR. Patent documents will only display the city and state for US inventors or the city and country for non-US residents.
Privacy is a good thing. And with the number of cases of identity theft and fraud rising, the USPTO's practice was seriously out of date... The WIPO implemented a similar policy for PCT applications a couple of years ago.
Scam artists and patent promoters have been using inventor mailing address data for 150 years to ply their schemes. Many of these schemes involved sending a letter from a bogus company to an inventor expressing interest in licensing their patent. The letter would ask the inventor to send a small fee, usually $5, to the company to pay for a legal opinion on the validity of their patent. Of course, the inventor never heard back.
My favourite inventor scam dates from the 1890s. A clever con artist located in Paris would send inventors a letter announcing that they had been awarded a medal by a prestigious (but bogus) scientific or technical society. In order to collect their medal, all they had to do was send a small sum to cover postage...
However, it will make it more difficult to identify the ownership of published applications. Unlike most patent offices, the USPTO does not require applicants to declare an assignee on their applications. However, it was possible to make an educated guess about the ownership of a published application by looking for a corporate address in the correspondence field.
The order was published in the Nov. 23 OG and takes effect in three months.