When practicing a bit of law on the side during her time with the Manhattan D.A.'s office and at a larger law firm, the nominee called her very small practice "Sotomayor & Associates" even though it had no lawyers but herself. That would appear to be an infraction, if a minor one, of the relevant New York ethical rules.
Before the New York Times had the story yesterday, blogger Eric Turkewitz had it, though the Times gives him no credit. More: Scott Greenfield, David Wagner, Beldar, DRJ @ Patterico, Legal Ethics Forum, and Turkewitz again ("What should she do now?").
And: A Washington Times editorial had it before the NYT, and did credit the blog source.