These files are waiting to be submitted to our reputation servers and most likely have accumulated due to the bloodhound false positive this week. If the submission site is not allowed these will not get sent up. This is normally not a issue but with the FP there were a lot of files being sent up.
I would recommend performing the following steps on the group the client is a part of. If inheritance is on you will need to do these steps on the parent group.
Open the SEPM > Clients Icon > My Company (or parent policy of machine) > External Communication Settings
Here in the submissions tab uncheck both of submission checkboxes and let the client get the new policy. This will tell the client it no longer needs to send up reputation data and will purge this folder on its own. On a sidenote I would recommend going through the doc below to make sure that your proxies are allowing reputation data to be sent as this information is very valuable for symantec to make accurate reputation on new files.
http://www.symantec.com/docs/TECH162286