When a stock yields more than 5%, investors start to become skeptical about whether the payout is indeed safe. While it's tempting to want to believe that it can be safe and that it can be an excellent source of future dividend income, you also don't want to get burned and see that dividend get cut or suspended.Consider pharmaceutical giant Pfizer (PFE 3.38%). Its dividend yield is around 7.5% right now, and if the stock continues to decline, it may not be long before it hits 8%. The big question is whether ...