Here's something rather specific:
In a universe I'm working on, technology is advanced. We're talking Star Trek, holodecks and replicators included. Due to a complicated situation, however, there is a deprived underclass of people* who adapt this technology for murdering people.
What sort of weapons would make sense for tech-savvy ghetto-rats living in a close-to-singularity world? Creativity is appreciated - the weapons are designed towards destroying morale rather than people.
*How do they exist in a Star Trek-style utopia? As I said, complicated situation.
Look at second life's issue with "griefers".
One noteworthy story involved a "bomb", that conjured a 50ft aparition of a "god", denouncing the sexual roleplay antics of the landowner, then proceeded to make it rain dildos.
I imagine that with replicator tech and abundant energy, the limiting factor will be raw material. That is probably where the new economy lies, which gives rise to the underclass, and where the above noteworthy story may find analog.
In second life each area has a "prim limit", to keep from killing the server under computational load. This is analogous to resource scarcity. Part of the greif of the attack was to consume the whole prim limit by spawning that many dildos.
In your futureistic setting, a similar "replicator bomb" placed in the wealthy person's material warehouse, programmed to consume all the available raw material, and produce a comically useless set of items from it would be an effective economic terror weapon that does not endanger human lives.
This would be especially useful if orchestrated when said wealthy person was attempting financial transactions that require rarified raw materials transfer to other wealthy people-- the act would tie up all those materials until they can be reprocessed back again, making the deal fall through. Continued and repeated harassment of this nature could financially ruin the wealthy person through denying them access to the exchange market, and tarnishing thier transaction record with defaulted transactions.