repeated computer generated small buying

Just wondering if anyone knows what is the whole strategy of buying 8 shares every 3-4 min that is currently going on. The value of the trade amount to about one dollar.
I presume it must be done by some broker otherwise the transaction fees for each trade would make this prohibitive.
Interesting question is why the broker is doing all this?
I presume they don't do this to very share.
If they are acting on client's instruction, I am curious as to their intention.
Anybody in the know how the system work?