The Open Threat Exchange (OTX) is an open information sharing and analysis network. It provides real-time, actionable threat information submitted by over 8,000 contributors in more than 140 countries. Users can opt-in to share anonymous threat data with the OTX community. An attack on any system in the network can now be used as an indicator for subsequent attacks on any other participant. By participating in OTX, defenders can learn from each other and quickly adapt to new threats.
Source: https://thehackernews.com/2014/07/crowd-sourced-threat-intelligence.html