I see your point. There needs to be laws in place as I don't think it's against the law to change someones homepage to a porn site.
However, as far as the idea of signing a petition against adware and spyware itself - that's somewhat ridiculous as the people who do this kind of stuff aren't nice, law-abiding people. They're villains who are trying in the long-run to get your money

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Anyways best of luck with the petition!