Infamous 2 UGC - How does it work?

UGC levels are mapped by green dots on the maps and user created ones are marked by a seperate color (I believe blue). The user created maps are filtered out based on your preferences: do you want newer levels or older levels? ones that build off of pre existing levels or ones made from scratch? Highest rated ones or most played? There's plenty of filters and around 20-30 are randomly selected to appear on your map so that you are not bombarded by the entire online community-made levels. PEACE