Notably, the decision features the unlikely division of four conservatives and one liberal (Breyer) in the majority, and three liberals and one staunch civil libertarian conservative in the minority (Scalia), Justice Scalia's dissent is well worth reading in its entirety. Here is a cautionary nugget:
The Court disguises the vast (and scary) scope of itsholding by promising a limitation it cannot deliver. The Court repeatedly says that DNA testing, and entry into a national DNA registry, will not befall thee and me, dear reader, but only those arrested for "serious offense[s]." Ante, at 28; see also ante, at 1, 9, 14, 17, 22, 23, 24 (repeatedly limiting the analysis to "serious offenses"). I cannot imagine what principle could possibly justify this limitation, and the Court does not attempt to suggest any. If one believes that DNA will "identify" someone arrested for assault, he must believe that it will "identify" someone arrested for a traffic offense. This Court does not base its judgments on senseless distinctions. At the end of the day, logic will out. When there comes before us the taking of DNA from an arrestee for a traffic violation, the Court will predictably (and quite rightly) say, "We can find no significant difference between this case and King." Make no mistake about it: As an entirely predictable consequence of today’s decision, your DNA can be taken and entered into a national DNA database if you are ever arrested, rightly or wrongly, and for whatever reason.
Today’s judgment will, to be sure, have the beneficial effect of solving more crimes; then again, so would the taking of DNA samples from anyone who flies on an airplane (surely the Transportation Security Administration needs to know the "identity" of the flying public), applies for a driver’s license, or attends a public school. Perhaps the construction of such a genetic panopticon is wise. But I doubt that the proud men who wrote the charter of our liberties would have been so eager to open their mouths for royal inspection.