steal (one) blind
To steal everything one owns, especially through deceitful or fraudulent means. Sometimes used to insinuate that someone is charging too much money for something. The CEO was sent to prison for stealing his clients blind through a complex Ponzi scheme. Another $100 in fees? These guys are stealing us blind!
steal someone blind
Also, rob someone blind. Rob or cheat someone mercilessly, as in Ann always maintained that children would steal their parents blind. The allusion here is unclear. Possibly it means stealing everything, including someone's sight. [Mid-1900s]