So you risk your (incredibly profitable) business just to skim a little on the spread? Doesn't seem worth it.
A lot of people who just do not understand how thing kind of market works make these allegations— due to things like issuing a market order and then having the trade execute at prices which are dissimilar to the last price but completely explained by the published orderbook.
I think it's very possible for exchanges to do this sort of thing, especially when their technology is so poor that it's difficult to audit how they match orders.
They are _a_ market. While they may historically be the leader, many bitcoin trades and negotiations never touch them any longer.
This no longer belongs to a single site. It's too big now.