CME has been having constant meetings with brokers upset over the boosted transaction fees and new market data fees announced late last year (they took effect immediately for new users, but could be delayed until 2015 for some others).
CEO Terrence Duffy at an industry conference last week: "If we're missing something that we didn't see, we're listening to it. That's yet to be completely analyzed."
RJ O'Brien CEO Gerald Corcoran whose customers will pay a lot more: "We built our systems on the understanding, belief and agreement with the CME that we wouldn't be charged market-data fees for providing our customers access to the market, and they've pulled the rug on us."
CME, of course, is banking on the higher and new fees to help boost revenue.