Many norms have been broken in American politics in recent years, and one of them is the use of private tax returns as a political weapon. The trend is destructive, as a pair of events this week illustrate.

The first is a useful lawsuit by hedge-fund manager Ken Griffin against the Internal Revenue Service seeking damages for the leak of his tax records to ProPublica. In June 2021 and in articles since, the left-wing website has published the confidential tax data of Mr. Griffin, who runs Citadel Securities, and other wealthy Americans.