It did not deter the Khmer Rouge fighters who found ways to cross it, for it was impossible to effectively police the long border.

But, sir, I don't know how we set about effectively policing something like that, given the size of the place, and the number of people who'll be there.

Many critics, including those inside New Jersey government, have argued that the insular nature of the division made it incapable of effectively policing itself.

The question also remains whether OPEC can effectively police the organization's members to prevent them from violating their individual production quotas.

Commerce Secretary William M. Daley said today that if the industry could show that it was effectively policing itself, "legislation would not be necessary."

Chinese police have, however, proven unable to effectively police higher tier prostitution practices.

The bumbling N.C.A.A. can put a cop on every college corner; only school administrations can effectively police a coach.

We are assured by the housing finance wizards that the government regulators will effectively police the private banks.

The group members used flexitime without clocks and effectively policed their own team discipline.

But recent events made officials wonder if the show was simply too large to be policed effectively.