As the stock market has become more accessible to the casual trader, several companies have developed socially- and envioronmentally-conscious mutual funds. These funds invest in companies which meet certain non-monetary criteria (e.g. no tobacco companies, no arms dealers, strict environmental policies, etc.) Quite a few of these funds now exist, each catering to a slightly different group of people who care about such things.
ViceFund uses exactly the opposite criteria. According their data, the wages of sin greatly outperform the S&P 500 over a 5-year period.