I know everything about Nixon seems quaint in comparison, but this was specifically one of the crimes mentioned in the articles of impeachment against Nixon.

Josh Marshall (joshtpm.bsky.social): So two DOGEbros now embedded at IRS are, according to WAPO, finalizing an 'omnibus agreement' for IRS to share Americans' individual tax data with officials across the US govt, something that would appear to be plainly illegal.
(WashPo DOGE IRS Tax Records)