I completely understand their need to do this, and have no problem at all in cooperating. I don't see it as an infringement on my "rights" since I choose to shop where I shop. It's nice knowing that the prices I pay there don't include the cost of them having to write off lots due to theft.
Making a stink over this is just plain ignorant.
You are welcome to obligue their request, however if the law states, as it does, and as it should, that a store may not force you to do so, then you and the store need to respect the rights of folks who choose not to obligue their request.
I am sure I can find someone who thinks subjecting your child to a full cavity search at school when there is a suspicion of drug activity in the school is a reasonable request.. Just because you find something reasonable does not mean that A) it is, or that B) others should be subject to what you consider reasonable.
The law is the law, if Wal Mart detains people unlawfully they are violating the LAW. Period. Wal Mart nor any other company has the right to violate the law.