The first time you login to Faveous you need to add the different accounts of each service you want to import. In order to do that you need to authorize Faveous to keep track of your accounts' progress. After that Faveous will connect to your accounts periodically (every 15 minutes actually) and automatically retrieve your favorites from each service, making them appear on your Homepage.
You have to do it only once. We do NOT have any access at any moment to your passwords.
We do NOT use your information for anything other than providing you with this great service.