The NY Times:

Agencies working to curb drug trafficking, cyberattacks, money laundering, counterfeiting and even copyright infringement complain that their attempts to exploit the security agency’s vast resources have often been turned down because their own investigations are not considered a high enough priority, current and former government officials say.

Just think of all the people who’d come knocking on your door because the NSA shared your data with some other agency. And don’t think the NSA won’t share this data at some point – it’s only a matter of time.