The sad thing is, its not really the big corporations that utilize illegal labor (I know, Tyson did but...). Its usually independent building contractors, mom and pop restaurants and "family" farmers.
What about Wal-Mart, Target, etc and Home Dept? I reallly don't know for sure about them, just asking.
Tyson shut down that day the illegals demonstrated and I know there other companies, but can't remember them.