Update OPEN_PROBLEMS/DECENTRALIZED_DATA_DELIVERY_MARKETS.md

Co-authored-by: Jorge Soares <[email protected]>

Author: yiannisbot

OPEN_PROBLEMS/DECENTRALIZED_DATA_DELIVERY_MARKETS.md

@@ -123,7 +123,7 @@ In review, the Metering & Fair Exchange fields end up contributing to each other
 *   Experience
   *   How to make the transfers start instantaneously?
   *   How to support others (e.g. Content Publishers) paying for the usage?
-  *    How to make it private (e.g. that others don’t know who is requesting what)?
+  *    How to make it private (i.e. so that others don’t know which users are requesting what content)?
 *   Performance
   *   How to overcome the send-and-halt in order to max bandwidth throughput 
       *   How to support multipath (i.e. fetching from multiple sources)