Spreads have narrowed in large part because of the ECN's. In addition, liquidity has improved dramatically because of their presence. Just from observation alone these important benefits can be attributed to the ECN's presence. For instance, so many market makers quote only 100 shares, while ECN's in the same stock will be quoting several thousand shares. Since ECN's are solely a matching system, they do not have any other way of receiving compensation.
Market makers can and do profit from the order flow in which they receive.
Market makers are just angered by these ECN's because they have narrowed the spreads which they used to profit from, and in addition to that, have taken a large part of the order flow away form them. In this environment I think it is proper to reward the participants who help create a more efficient and just market place and not the market makers who more and more are becoming a less important factor in the marketplace. If the commission believes that it is beneficial to have separate Agency Quotes then allow all market participants to have this same right. However, in any case do not allow fees to be charged, since this benefits no one except the market makers and it does so at the expense of the customer. Let's work to lower costs not increase them.