Second Life has a functioning economy where every linden has a real currency value and updating conversion rates. meaning you can't really generate lindens just like you can't generate pounds or dollars on a credit card, so it needs to be either bought officially or stolen from an account that already has it. With the latter being extremely easy to detect, report, get you banned for good, and almost impossible to do. and on top of that could be traced back to you which puts you on grounds for legal persecution, and the former being also fairly impossible, and probably easier to detect directly by the company servers due to the hard to miss alterations it would make to the Linden economy and the conversion rates.
tbh it really isn't worth the amount of off-game trouble it could potentially bring. unfortunately, due to its monetary system, Second Life isn't a game one can motherlode themselves to riches :/
