Can a journalist reveal a source of information after guaranteeing confidentiality if the source proves to be unreliable?

Collections of quotations in which prominent journalists reveal their beliefs about politics and/or the proper role of their profession.

Poets, philosophers, journalists and even science writers are revealing their intimate histories with canines.

But when the President hung tough, the journalist revealed their past meetings and payments.

In the past, crusading journalists who ventured into the mental-health-care system revealed it to be a disaster, a snake pit.

But we warned then that the inquiry should not degenerate into an attempt to compel journalists to reveal their sources.

If story likely to be challenged legally or by PCC then journalist must reveal source to editor if asked.

July 24: Several journalists reveal an alleged payoff list of Miguel Rodríguez.

In 1991, a journalist revealed that passengers who disembarked at the location were not informed they were in Haiti.

Will all journalists now be revealing their sources?