Actually, no, you wouldn't have to have anything other than "good will" or the potential for some reward to come to you in some fashion. When the mob puts out a hit, they don't sign a contract with an actual person, they just put out the "bid". THen when the body washes up on the shores of the East River and the NYPD identifies the body, the bosses find out who did it and an envelope with cash and a call girl show up in a town car at the hitmans house and they enjoy a few weeks stay and an "emperor's package" at Ceasars Palace.
Imagine if next week I found information that got Tyco CEO Dennis Kozlowski out of jail and reinstated to his former place of power and money because I found proof he DID pay taxes on that Artwork and the the Board of Directors committed fraud and conspired with the SEC to have him be the fall guy for their own crime. That guy or any other falsely accused millionare rotting in jail like GOrdon Gekko, is going to be stuffing envelopes with cash and having BRenda and Carle from the SPearmint Rhino picking me up in a limo feeding me cherries and pot brownies on my private flight out to the "emporer's package" at Ceasars Palace.