Johnson & Johnson and Altria Group are two prominent dividend stocks, but I wouldn't rely on their payouts.Investing in dividend stocks can seem like a great way to pad your portfolio's returns, especially when you're investing in dividend growth stocks that increase their payments over the years. The risk, however, is that investors often look at a stock's track record for paying dividends, and use that as a justification for why it may be a safe income investment to hold for the long term. But the past do ...