I understand your position, Larry, and I agree that you need the warning. But "DO NOT COPY COPYRIGHTED MATERIAL" would work just as well, and would not be personally offensive to me and other dedicated, moral, hard-working, law-abiding, intelligent people working to abolish copyright law as it is today.
Imagine it like this: bigamy is illegal in every state. It is frowned upon by most religions and most people. But there are some people who are quite decent, loving, moral people working to change the laws and attitudes to make it legal. For them (and especially those not actively practicing) to see themselves called "perverts" or "criminals" in public is offensive, and doing so is most definitely a biased expression of political opinion, even though it happens to be the opinion of the vast majority.
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