The accusation is that Bloomberg uses data from the people using the terminals to inform their own trades. It popped up a little while back but I can't find the original articles.
> The Guardian also understands that JP Morgan also has concerns about how Bloomberg used information from its terminals while pursuing stories about Bruno Iksil, the trader known as the London Whale, who was blamed for massive losses at the bank last year. Bloomberg said it had blocked journalists' access to client data within 24 hours of receiving a complaint from Goldman.
http://www.theguardian.com/media/2013/may/10/bloomberg-goldm...
> The Guardian also understands that JP Morgan also has concerns about how Bloomberg used information from its terminals while pursuing stories about Bruno Iksil, the trader known as the London Whale, who was blamed for massive losses at the bank last year. Bloomberg said it had blocked journalists' access to client data within 24 hours of receiving a complaint from Goldman.
Interestingly, Goldman Sachs recently launched its own "Bloomberg Terminal killer", Symphony: http://qz.com/501783/the-goldman-sachs-backed-bloomberg-term...
Funny quote from the QZ article:
> At a cost of more than $20,000 per year per terminal, Bloomberg is an extremely expensive system for users mostly interested in its chat features.