Whistleblowing rewards
Others have mentioned incentives, but as for actual rewards, there are such things, for example in the US there are various Federal whistleblower rewards/compensation programs. Whistleblowing to the IRS cases of underpaid taxes over $2M the whistleblower may be rewarded 15-30% of anything collected. The SEC likewise has paid enormous sums.
Plenty of law offices, organizations, and agencies are eager to explain the financial benefits of whistleblowing:
https://www.sec.gov/whistleblower
https://www.whistleblowersinternational.com/what-is-whistleblowing/rewards/