The majority of HIPO members were recruited from the ranks of Danish Nazi collaborators.

Some men were uniformed in order to be visible while others worked secretly in plain clothes.

In retaliation and as a warning, the corps terrorized the civil population and blew up houses, factories, and even the Tivoli Gardens.

After the war, service in the HIPO corps was one of the crimes of collaborationism that retroactively became capital offenses.

A somewhat larger number received death sentences that were later reduced to long prison terms or parole.