Have you tried to shared with a friend a business opportunity? Explaining to him/her the potential earning that could be derrived from the business plan? She willingly join the plan after giving it a second thought & understood the risk involved & there's no way to recover back the investment pumped in.
The monies has been used for investment. Few months down the road, when the plan doesn't goes well, he/she use force & demanded his/her monies back ! Accusing you of cheating his/her monies, branding you as liar & all sorts of nasty words.
Really hate this kinda people.