Real estate brokers don't have the same power they had in the days before the Internet. Today, buyers and sellers can use the web to view listings and perform other tasks that used to be exclusively performed by a broker.
Brokers do have one thing that everyone wants, which is direct access to the Multiple Listings Service (MLS). This is kind of like having your own spirit guide telling you where the secret treasure is buried (and you pay it a yearly fee for the privilege).
The MLS is a database that stores information about properties for sale. Furthermore, it's a regional joint venture of real estate brokers affiliated with the National Association of Realtors. You can't access the MLS unless you're a licensed member of your local MLS service—kinda like getting backstage because you know a guy who knows a guy.
Many real estate companies put an MLS-like database on their websites for homebuyers to look through, but it's not the same thing. There's not a more comprehensive list. Having the MLS at their fingertips makes brokers informative and powerful.
Just don't give them the address without having them sign a contract saying that, since you told them, if they take the contract they owe you. Because if they don't, they don't owe you anything.