Is the Government selling or not?

From Goss article, page 178.
"Government agencies have realized the commercial value of the data they gather for the purpose of public administration and sell data to offset the cost of production. Both the U.S. Bureau of the Census and the U.S. Postal Servicehave provided privileged access to their data to information conglomerates, allowing private interests to profit from a socially produced resource." And later on: "Local governments have initiated [to sell] their information to private users and [negotiate] contracts with companies that creates and maintain data bases in return for rights to sell this information to other clients."

How is that possible? Is there any law to avoid that?

Then, in the same article: "Legislation restricting the unauthorized release of personal data by public and private institutions includes the Privacy Act, which regulates disclosure of individual records by the federal government."

Does this mean that, with the Privacy Act, government institutions and local institutions could not sell any longer information?