Historical clue formulations

• Flimflammers — 2022-04-15
• The title characters of 1988's "Dirty Rotten Scoundrels," e.g. — 2019-03-17
• People who target the starts of 17-, 30-, 40- and 57-Across — 2017-10-17
• Scam artists — 2016-06-06
• Swindlers — 2009-12-16
• Cheats — 2000-04-02