slippery business

1. Any activity or pursuit that is or tends to be tricky, unstable, or difficult to achieve. Any politician will tell you that trying to regulate this sector has always been a slippery business.

2. Any corporate industry that is or tends to be elusive, cunning, or untrustworthy. This vulture fund industry is such a slippery business. The number of loopholes and workarounds they leverage to bypass regulations is staggering.