WASHINGTON (Reuters) - Facebook Inc (FB.O) said on Tuesday it is launching a "data abuse" bounty program to reward people who report misuse of data by app developers.

The announcement comes ahead of two days of congressional hearings starting on Tuesday, where Facebook Chief Executive Mark Zuckerberg will be asked how up to 87 million Facebook users’ data was improperly shared with political consultancy Cambridge Analytica.

The program will reward people with first-hand knowledge and evidence of a Facebook platform app collecting and transferring user data to another party to be sold, stolen or used for scams or political influence.

(Reporting by David Shepardson; Editing Meredith Mazzilli)