1. A system for cross platform user joining, comprising: a processor configured to: associate a first user identification (UID) and a second UID with one or more Internet Protocol addresses (IPs); associate the first UID and the second UID with one or more monitored behaviors; and join the first UID and the second UID based on the one or more IPs and the one or more monitored behaviors; and a memory coupled to the processor and configured to provide the processor with instructions.