Hackers, 2000: DMA allows arbitrary memory access!
Vendors: Isn't that great? Kernel debugging is so convenient!

Hackers, 2010: FBI and NSA can use ExpressCard and IEEE 1394 DMA to access memory at will and steal full-disk encryption keys from participants in movements like "Occupy Wall Street"!
Vendors: How many dissidents across the US are actually going to get targeted by the FBI like that?

Hackers, 2020: USB 4 allows arbitrary memory access via DMA, any standard USB device can be used to steal data!
Vendors: Physical security isn't our responsibility - you can just seal off the USB ports.

Hackers, 2025: PCIe DMA enables online game cheats that the system can't detect!
Vendors: Right now! Immediately! Enable IOMMU! Anyone who doesn't enable it gets their account banned!