I presume you are saying the canvassers for ACORN are paid on a piecework basis. I know this is one of the right wing bugaboos, but it would help to get the facts right when denouncing them. They pay hourly.

http://marcambinder.theatlantic.com/archives/2008/10/acorn_rallies_its_troops.php

When a Republican complains about voter fraud, what he is really saying is too many brown people are allowed to vote.

Edited to add this:
-Quote
ACORN registers lots of lower income and/or minority voters. They operate all across the country and do a lot of things beside voter registration. What's key to understand is their method. By and large they do not rely on volunteers to register voters. They hire people -- often people with low incomes or even the unemployed. This has the dual effect of not only registering people but also providing some work and income for people who are out of work. But because a lot of these people are doing it for the money, inevitably, a few of them cut corners or even cheat. So someone will end up filling out cards for nonexistent names and some of those slip through ACORN's own efforts to catch errors. (It's important to note that in many of the recent ACORN cases that have gotten the most attention it's ACORN itself that has turned the people in who did the fake registrations.) These reports start buzzing through the right-wing media every two years and every time the anecdotal reports of 'thousands' of fraudulent registrations turns out, on closer inspection, to be either totally bogus themselves or wildly exaggerated. So thousands of phony registrations ends up being, like, twelve.
-endquote

A nice rundown on the biannual mouthbreather freakout over ACORN from Josh Marshall at TPM
http://talkingpointsmemo.com/archives/223436.php