the tide has turned!, page-28

"i.e. as soon as the algo sees an order coming in, it adjusts its own order virtually simultaneously (within microseconds - my understanding is that they have a massive speed advantage as its feed is right next to the exchange, but I could be wrong) and pushes itself to the end of the queue or in some cases disappears."

I see this all the time in my day trading of other stocks. I haven't noticed orders moving to the back of the queue but I very regularly see orders disappear as soon as they are touched (e.g. a 10,342 shares order gets pulled the instant even just 5 shares gets traded into it).