Bill Poser at the blog Language Log takes issue with the Supreme Court’s decision in Morse v. Frederick, not because of the legal ideas involved but, more importantly, because they misinterpreted the semantics of the phrase "Bong Hits 4 Jesus":
The kind of meaning that the Court purports to find is propositional. It claims, in effect, that the interpretation of the banner is something like "It is good to smoke marijuana even though it is illegal." or "Go ahead and smoke marijuana.". However, the banner does not, on any plausible analysis, contain the kind of syntactic structure that serves to express propositions, namely a sentence, not even a sentence part of which is not overt. Nor is this an example of a construction with an implicit verb, such as "Freedom for Tibet", which means something like "Freedom for Tibet would be good" or "We support freedom for Tibet". (The Court does not argue that the banner means "It would be good for Jesus to smoke marijuana.")
Poser makes a number of other interesting points about the semantics of the phrase and how it can and cannot plausibly be interpreted. Of course, the only interpretation of the banner that really matters at this point is the Court’s.