Federal judges can now sentence crack-cocaine defendants under new guidelines, CNN reported. The guidelines were revised to reduce the differences in terms meted out for crack convictions compared to people convicted on charges involving powder cocaine.

In addition, about 1,600 federal inmates can ask a court to reduce their sentences because of a retroactive provision included in December's decision by the U.S. Sentencing Commission.

Advocates of the reduced sentences say it was a decision based on fairness. The U.S. Justice Department counters, however, the move will allow dangerous criminals back on the street.

While the commission set Monday as the date for the retroactive measure to become effective, some of the eligible prisoners already have been released because the panel's date was considered advisory and judges had the discretion to hear petitions and release inmates earlier, CNN said.