Canned Messages with multiple users at once. Who has contacted who?

Canned Messages with multiple users at once. Who has contacted who?

My question is when we have multiple agents online at once and they are sending out canned messages to prospects who are online but haven't responded so a chat isn't started yet. How do we know which prospects have had a canned message sent to them and which ones haven't. Is it possible that our agents are all sending canned messages to the same prospect in an attempt to start a chat with them? 

Thank you, 

Matthew