While various existing codes have some differences, most share common elements including the principles of — truthfulness, accuracy, objectivity, impartiality, fairness and public accountability — as these apply to the acquisition of newsworthy information and its subsequent reportage to the public.

Like many broader ethical systems, journalism ethics include the principle of "limitation of harm." This often involves the withholding of certain details from reports such as the names of minor children, crime victims' names or information not materially related to particular news reports release of which might, for example, harm someone's reputation.
http://en.wikipedia.org/wiki/Journalism_ethics_and_standards

Freedom of the press is the guarantee by a government of free public press for its citizens and their associations, extended to members of news-gathering organizations (journalists), and their published reporting. In many countries there are constitutional or statutory protections pertaining to freedom of the press.

With respect to governmental information, any government distinguishes which materials are public or protected from disclosure to the public based on classification of information as sensitive, classified or secret and being otherwise protected from disclosure due to relevance of the information to protecting the national interest. Many governments are also subject to sunshine laws or freedom of information legislation that are used to define the ambit of national interest.
http://en.wikipedia.org/wiki/Freedom_of_the_press#United_States

US Costitution 1st amendment bill of rights
The Bill of Rights protects the freedoms of speech, press, and religion; the right to keep and bear arms; the freedom of assembly; the freedom to petition; and prohibits unreasonable search and seizure; cruel and unusual punishment; and compelled self-incrimination. The Bill of Rights also prohibits Congress from making any law respecting establishment of religion and prohibits the Federal Government from depriving any person of life, liberty, or property, without due process of law. In Federal, criminal cases, it requires indictment by grand jury for any capital or "infamous crime," guarantees a speedy public trial with an impartial jury composed of members of the state or judicial district in which the crime occurred, and prohibits double jeopardy. In addition, the Bill of Rights states that "the enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people,"[2] and reserves all powers not granted to the federal government to the citizenry or States. Most of these restrictions were later applied to the states by a series of decisions applying the due process clause of the Fourteenth Amendment, which was ratified in 1868, after the American Civil War.

Madison proposed the Bill of Rights while ideological conflict between Federalists and anti-Federalists, dating from the 1787 Philadelphia Convention, threatened the overall ratification of the new national Constitution. It largely responded to the Constitution's influential opponents, including prominent Founding Fathers, who argued that the Constitution should not be ratified because it failed to protect the basic principles of human liberty. The Bill was influenced by George Mason's 1776 Virginia Declaration of Rights, the 1689 English Bill of Rights, works of the Age of Enlightenment pertaining to natural rights, and earlier English political documents such as Magna Carta (1215).

Limitations of freedom of press glen greenwald http://glenngreenwald.blogspot.com/2006/09/aei-iran-and-free-press.html