The "Meltdown" and "Spectre" security flaws

I'm finding the proof of concept attacks on memory cached as a result of speculative execution of code branches fascinating and instructional. First of all, I haven't been paying much attention to how processors work, and find it amazing that it's normal to evaluate the else blocks in our code even before the if blocks have evaluated to True or False. I'm learning a lot about computers from articles like this one in Ars Technica and the Meltdown Paper. The latter gets over my head quickly, but is written clearly enough that I'm getting quite a bit out of it.

It's disconcerting to know that your programs in the cloud have had access to private data in mine via side channels like these. And mine access to yours.