Update OPEN_PROBLEMS/DECENTRALIZED_DATA_DELIVERY_MARKETS.md

Co-authored-by: Jorge Soares <547492+jsoares@users.noreply.github.com>

Author: yiannisbot

OPEN_PROBLEMS/DECENTRALIZED_DATA_DELIVERY_MARKETS.md

@@ -207,7 +207,7 @@ Here we list the attacks to consider when designing a solution. These are:
 
 *   Malicious actor forces provider to spend bandwidth without issuing payment (also known as Griefing Attack)
     *   Type: client fraud 
-    *   Consequence: bandwidth-spent 
+    *   Consequence: bandwidth is spent 
 *   Malicious actor forces provider to pull the file from storage point (e.g. Filecoin, Cloud Storage, etc), paying the cost without the provider ever getting paid 
     *   Type: client fraud
     *   Consequence: currency is spent