There's a much better and more ethical form of nullification if citizens refuse to enforce a law. Just say so at voir dire. It's virtually guaranteed it will be asked when a jury is being selected "If the evidence shows guilt, will you vote to convict?" If you say "yes" then nullify, you've lied under oath even if you're never caught. And your opinion is secret forever. Just say "no". If they can't get 12 people willing to convict, the law is nullified and public opinion is clear and no law has been broken or bent.