[DataPacRat]

I'm putting together a setting that's roughly TL10, no FTL or other superscience save for two items, which are close enough to what Spaceships calls a Singularity Drive and a Vacuum Energy plant that I'll just swipe the stats.

Of course, with no delta-v limits, it's possible to throw together something like the World-Killer from SS3, for under $1B. (SM+12, mostly Stone Armor, $550M for the automated drive, $75M for an automated SM+11 control room, $50M for stealth, $35M for chameleon, maybe $15M+$3M for a few SM+9 UV lasers and fission plants to discourage would-be heroes.) Sure, it's only got an accel of 0.5G, but once it's built, you can send it racing off away from a solar system to stop at a distance of 0.75 lightyears, then turn it around and have it arrive at 0.9c. An online relativistic calculator I found implies the impact would be 2,521 teratons, 25 times that of the dinosaur-killer. (Or, in Spaceships terms, collision damage of 9d*100,000,000.)

The trouble is, I'm actually aiming for a generally /hopeful/ setting - something closer to the Iain Banks' Culture than Eclipse Phase. And now I'm having trouble coming up with a way to reconcile "life is generally at least as cool as having a volcano lair populated by catgirls" with "any billionaire (or billion-dollar-scale company or group) who has a mind to, can exterminate life on a planet", without dropping too far into mind-control ickiness that negates the main theme. I mean, sure, once you raise everyone to a better-than-today's-first-world standard of living, cure aging and disease, offer optional uploading-based immortality to anyone who wants it, and have a galaxy full of living space to spread out into to avoid over-crowding, /most/ reasons anyone sane would have to threaten a planet with doomsday just go away.

Anyone have any ideas for how the remainder of potential world-killers might generally be dealt with? Eg, ultra-tech versions of today's "nudge units" with the target of nudging people towards at least a minimal level of sanity and cooperativeness? Wide-spread surveillance to keep track of everyone's behaviour, with increasing focus on people who are more likely to want to cause gigadeaths, leading towards more heavy-handed interventions? Flashmob-style disorganized organization to crowdsource lovebombing and other psychological boosters? Generally giving up on any large planets or stations, focusing instead on smaller habitats that can /duck/?

What options would cause the least strain to your willing suspension of disbelief?

(Other than having relatively secret offline backup sites hidden in various locations to reboot interstellar civilization from, if need be. I've already got that aspect well-covered. :) )