From the Model Mayhem FAQ:

What is a Certified Partner of Model Mayhem?
We partner with certain third parties that are intended to provide our members with additional services. We call these partnerships Certified Partners, and currently there are only 3 Certified Partners we work with: Nextag (shopping), DriveThruSocial (personal websites), and EzPrints (comp cards)

In some cases, these Certified Partners have special access to our systems (APIs) and may ask members to supply their log-in information in order to retrieve information like photos from their portfolio. If you are ever asked for your personal MM information from someone, please check back here to see if they are a Certified Partner. +