LisaAA is right - I just copied this from the Parental Controls on Verizon's website:

Set Trusted Numbers

Trusted Numbers are phone numbers on your wireless account that can always reach your child, regardless of other Usage Control restrictions (such as Time Restrictions) you set. Trusted Numbers is another way to help you manage your child's wireless service.

• Feel safe knowing that you or any numbers you designate can always reach your child
• Add up to 20 numbers to your Trusted Numbers list for each account member enrolled in Usage Controls

This should improve the way Usage Controls / Parental Controls works!