A federal judge Thursday temporarily blocked the government from enforcing a new insider trading law that would require about 28,000 executive-branch employees to disclose details of their financial transactions on the Internet.

U.S. District Judge Alexander Williams Jr. in Greenbelt granted opponents of the law a temporary preliminary injunction that prevents the Stock Act from being enforced until Oct. 31. The law, which President Obama signed in April, had been set to take effect Aug. 31.

The judge wrote that the Stop Trading on Congressional Knowledge Act appeared to illegally infringe on federal workers’ right to privacy. The injunction does not, however, affect the law from taking effect for members of Congress and their staffs.

The law was written with them in mind. Congress amended it to extend to senior executives in the executive branch, including the military.

The law was designed to restrict those it affects from profiting from non-public information they obtain through their jobs.

Congress could choose to exempt the executive branch from the law while the injunction is in effect.

Executive-branch employees, represented by the American Civil Liberties Union, argued that posting private information about their real estate investments, retirement funds and stock holdings would violate their privacy. They said the public would have unrestricted access to personal information that could make the government vulnerable to security breaches.

The Senior Executives Association and several other employee groups, as well as a bipartisan group of former national security and law enforcement officials, formed the opposition.
The government already collects financial information from executive-branch employees. But it is rarely inspected by the public. The plaintiffs said that creating databases for the public to search, sort and download was an unnecessary intrusion.

Attorneys representing the Office of Government Ethics, which the law appointed to post the financial information on the Internet, argued against the injunction.