The DRAM thing isn't a great good example, because it requires an outside actor doing something unusual and deliberate at short range to receive the message. It

The DRAM thing isn't a great good example, because it requires an outside actor doing something unusual and deliberate at short range to receive the message. It's interesting mainly because it doesn't require control of anything beyond memory-access pattern, which means that some machine learning algorithms could do it without needing the intermediate step of gaining arbitrary code execution or even acquiring the control necessary to make a signal out of their heating/cooling.