stock buybacks were illegal until 1982. At root, stock buybacks are just wash-trading, the company buying its own shares to move their price, without doing anything to justify that price movement.
https://pluralistic.net/2025/09/06/computer-says-huh/#invisible-handcuffs
Salesforce stock buyback to saddle company with debt until 2066
https://www.theregister.com/2026/03/16/salesforce_bonds_saas_share_buybacks/
