I had been wondering about this. The liquidity providers for ECN brokers (eg, mb trading, FXCM active trader, etc)... they're just market makers / bucketshops themselves, right? Do we only trust the level 2 information coming from the liquidity providers?

I know with FXCM Active Trader, you can not post links inside the spread for other customers. . Just the'liquidity providers' are allowed to be market makers. How exactly is that ECN?

Is the the same with MB Trading? What kind of guarantees can we get that MB Trading / FXCM aren't forwarding our trailing stops and acct information for their liquidity providers?