If they have unique identifiers, it would probably, eventually, get out of hand. Really, they could use data mining tools to detect specific patterns across their players' inventory databases, watch the patterns when anomalies are detected, and then correct the issue as well as ban the offenders.

It's easy to track database transactions with tools like Splunk. Most anomalies would appear like massive transactions, anyway. Utilizing tools that monitor container changes that are much larger than a certain threshold is much easier than manipulating a system that's already ok with adding another variable that may cause inventories and drops to consume even more memory to render. Plus, if you go back through and issue the identifiers, it will take a crazy amount of time to reformat already existing inventories, not to mention the stuff that's already there.