Trust factor is a system based on reports, the more reports, the worst trust factor you have, Trust Factor is an extension to Prime Matchmaking - the system that allowed the players to connect their phone numbers to the Steam Account in order to only play with other “verified” accounts. You can improve your trust factor by getting commands, steam comments, report steam comments, playing without being reported, etc. To improve your trust factor fast and easy you need to become a more active member in the community and should therefor like, comment and create this guides, posts and screenshots.

Hope this helps a little bit:D