This article addresses the legal ethics and First Amendment implications of recent Treasury Department regulations governing legal opinions on tax-motivated transactions. As discussed in the article, the regulations are intended to address the significant policy and budgetary issue of practitioners’ involvement in the development, marketing and encouragement of abusive tax shelters. However, the article concludes that the regulations are in many respects an inappropriate response to these problems because their prohibitions prevent a lawyer from giving taxpayers a complete, informed assessment of their rights. As such, they create significant ethical conflicts and deny the public legal advice. More generally, they distort the lawyer’s r...