It would be marketing suicide to say they could read them wouldn't you think? I sure do. And I don't consider it lying because if you don't read them then they are private.
Look at it from their point of view as well as any other forum you have been to that has them pms as an upgrade service.
Private messages is one of the huge marketing tools they use besides access to premium boards and unlimited posts to up grade.
Market Data 
Markets 
AI
