You'll find mention of the issue in many journalistic ethics codes, and many newspaper's policies. For a US example from the SPJ's Code of Ethics[2]:
> Balance the public’s need for information against potential harm or discomfort. Pursuit of the news is not a license for arrogance or undue intrusiveness.
> Show compassion for those who may be affected by news coverage. Use heightened sensitivity when dealing with juveniles, [..]
> Realize that private people have a greater right to control information about themselves than public figures and others who seek power, influence or attention. Weigh the consequences of publishing or broadcasting personal information.
> Avoid pandering to lurid curiosity, even if others do.
> Consider the long-term implications of the extended reach and permanence of publication.
In the UK, for radio and TV, the Ofcom Broadcasting Code contains similar guidelines in less straightforward language.