I can't stand wasting development cycles on copy protection. For me it's like spending money on heavy duty locks and security systems for your house when you know that the professional criminals will simply knockout a pane of glass and be in and out before anyone responds to the alarm. Those TV commercial criminals that scram the instant The Clapper turns on the house lights are jokes—real crooks get the job done first.
My solution for home protection is a big dog called Magic. If she doesn't know you, you're not getting in the house. If she does know you, the worst you'll suffer is a case of severe slobber contamination (unless you properly pet her belly).
I wish I had the software equivalent of Magic. Not that I want my users to end up with drool on their hands, but I'd love to have simple, friendly protection in Debt Quencher. I know that any casual effort I put into protecting it will get broken by serious hackers and too much lock down will frustrate the honest buyers.
At my current job, I've fought against some of the extreme protection schemes that require users to have hardware dongles or to allow periodic "phone home" cycles. I keep losing the battle to refocus development time on cooler features instead of stronger window bars. For my own products, I'm determined to spend less time worrying about who is ripping me off. If someone can steal stuff and still sleep well at night, I'm not going to lose sleep thinking about them.
I'm also not stupid enough to think casual theft doesn't happen. I subscribe to the old proverb: "Trust God, but tie up your camels." Many of us would "forget" to pay for software unless encouraged to do so. I'm planning to limit features until the software is purchased as my encouragement. The protection will be non-invasive and nearly as friendly as Magic. Unlike my dog, I'll make sure the software doesn't leave warm gifts in the back yard or bark at rabbits in the front.