The phrase "impossible heist" refers to a robbery or theft that is thought to be extremely difficult or cannot be done successfully due to strong security measures or other obstacles. Full definition
The film follows the intersecting lives of an elite unit of the Los Angeles County Sheriff's Department and a successful bank robbery crew as the outlaws plan a seemingly impossible heist on the Federal Reserve Bank in downtown Los Angeles. (variety.com)
In Triple 9, a crew of dirty cops is blackmailed by the Russian mob to execute a virtually impossible heist and the only way to pull it off is to manufacture a 999, police code for «officer down.» (fatmovieguy.com)
The R - rated «Den of Thieves,» starring Gerard Butler, O'Shea Jackson Jr., and Curtis «50 Cent» Jackson, follows the intersecting lives of an elite unit of the Los Angeles County Sheriff's Department and a successful bank robbery crew as the outlaws plan a seemingly impossible heist on the Federal Reserve Bank in downtown Los Angeles. (variety.com)