Stealth mining on others' PCs can be completely voluntary and non-criminal. Assume software scans for GPU. No GPU? Not eligible (or maybe eligible, depending on coin sought to be mined). Not particularly useful to SHA256 anymore, but still relevant to ASIC-resistant Scrypt and other, more exotic algorithms which don't have ASICs built for them.
Create, say, a $25 minimum payout requirement among some other trickery and these disincentives to claiming rewards can bring real cost vs advertised cost down dramatically.
"There are many tales in literature over millennia about people selling their soul to a malevolent deity for the right price. But at least it’s usually a good price. Recent research has discovered that we are willing to compromise our computer for no more than one cent in income.
The researchers from the Carnegie Mellon University CyLab who carried out this work, tempted users into downloading and, in many cases, actually running a Windows application on their computer. After they had agreed to take part, they were told that it was for an academic study but were given very little other information about the application. The application pretended to run a series of computational tasks and paid those who installed it one cent for every hour it was left running.
Even though a participant's machine would give them a pop up warning when they started the download to tell them that this application wanted higher level access to essential security services, 22% of them went ahead and downloaded. And when participants were offered $1 per hour, that figure rose to 43%.
...
The fact is, this application could easily have contained malware. Participants knew little about what they were installing other than it would pay them for their processing power but they didn't seem to mind.
...
Crooks will be pleased to learn from this study that it is apparently very easy to trick ordinary computer users into hosting your malware.
..."
Full article @
https://www.techdirt.com/articles/20140624/16091327675/would-you-compromise-your-computer-one-cent-hour-new-study-says-many-are-happy-to-do-exactly-that.shtml