"The relevant copyright rulings weren't in place until the early '90s, and License to Ill and Paul's Boutique were released in 1986 and 1989, respectively" They're talking about laws that already existed being applied in a new way or to a previously unexisting technology/methodology. So what this record company is banking on is; that the ruling in the Biz Markie case, and the precedent it creates in case law, can be used as substantiation for their arguments. If that line of argumentation is permitted by the judge....the Beasties might be coughing up a gang of loot. Ex Post Facto laws are unconstitutional. Article 1, section 9, clause 3 prohibits the central government from doing so. Article 1, section 10, clause 1 prohibits the state governments from doing so.