A tip, not ethical (or legal ?)
The following, I imagine, is illegal - is a bit like "check-kiting" - the process of writing a bad check and sequentially depositing money (via checks) from a series of bank accounts, in a timed fashion, in order to severely extend the time it takes for the reality of the check being worthless to emerge. In pre-computer times one could "float" a bad check for months on end with just a handful of bank accounts. Technology has changed all that; but there are still local "clearing houses" so ...
... IF I write a check and want to extend the time it takes to clear I run a powerful magnet several times over the data-encoded strip on the bottom of the check. This scrambles the data so that the check must be pulled from the queue and cleared manually.