OnGuard

http://beonguard.com/

A Customer Reputation Management Community - TripAdvisor in Reverse OnGuard is a customer reputation community of businesses that allows them to keep track of risky customers. Primarily focused on the rental and lodging industries, OnGuard helps its customers to make an informed decision about who they want to do business with in an effort to protect their business, reputation, and their customers. OnGuard aims to help its customers with risk and loss prevention by providing an internationally accessible, centralized method of prescreen potential customers based on their past dealings with other similar businesses.

Angel list: https://angel.co/company/onguard