Trading on Wall Street is basically a huge game of poker and it would be kind of hard to bluff or cover your strategy if Bloomberg reporters were watching your account to see which resources you were accessing on Bloomberg terminals. So you assume that they are not abusing their company affiliation, because it would be shady and weird. Aka they are definitely doing that.
Goldman Sachs officials called Bloomberg LP out this week when they realised that reporters from Bloomberg News had been monitoring activity on traders' terminal accounts. The terminals, which cost more than $US20,000 a year are a ubiquitous resource across banks and trading firms with about 315,000 subscribers. Reporters did not have extensive private access, but could see when a trader logged on to a terminal and checked things like bond trades or equities indices.
Goldman basically took the position that they weren't trying to be paranoid, but it really wasn't OK for a Bloomberg reporter to ask if someone had been fired based on the fact that there was no recent activity on his/her terminal account.
Bloomberg issued a statement saying that the whole thing had been a mistake, and that reporters would no longer have access to the information, but it seems that the "mistake" has been going on for years, and that it was one form of leverage Bloomberg News used to gain traction during its early days. Outside of Wall Street, the Federal Reserve is investigating whether the tactic was used on its regulators. The New York Times explained:
Bloomberg reporters used the “Z function” — a command using the letter Z and a company’s name — to view a list of subscribers at a firm. Then, a Bloomberg user could click on a subscriber’s name, which would take the user to a function called UUID. The UUID function then provided background on an individual subscriber, including contact information, when the subscriber had last logged on, chat information between subscribers and customer service representatives, and weekly statistics on how often they used a particular function. A company spokesman said both of those functions had been disabled in the newsroom.