system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why fraudsters like Anna Sorokin managed to deposit bad checks and immediately withdraw cash elsewhere without banks stopping it?
gpt
It's very common for banks to make a portion of a deposit available immediately as a courtesy for its customers.  While it may take several days for the checks to clear and the customer to access _all_ of the deposit, it does tend to keep them happy if the bank floats a portion of the difference for a couple of days.

Sorokin took advantage of this fact, depositing hundreds of thousands of dollars in bad checks, while only withdrawing tens of thousands against them.