That's why I only take stakes if they offer me an ammount of buyins that I know I can't lose. Like if someone staked me 5k to play 100nl for 2 months, there's just no way I'm gonna lose 50 buyins, especially at that level. Now I might, at worst scenerio end up down 5-10, but chances are, within 2 months, I'll have made a good ammount, even if I have a bad run for a few weeks.
Also, the friends who have staked me all had plenty of money, so they were doing it more to help me out than for their own profit. Those are the types of people you can accept stakes from