I've (Xifon) been working with IW (Ban Candy) to develop a very easy way of reporting players. Previously you had to save the steam ID of a player, go to the theater, make a video of it, go through the very slow upload process (usually Youtube) and post it to a wall of a Steam group.
It's now easier to report players!
I'm announcing the MWsa Reporting tool, which allows you to quickly browse through saved matches in your theater (offline vault) and allows you to send them directly to Ban Candy.
(report a player)
Quickly look through your theater files to select the match that had hackers
View some information about the match you played and select the hacker
Click the "View profile" button to view the hacker's Steam profile
Click the "Report" button to open the reporting window
Enter a short message to send to Ban Candy, which could help the review process
Small file uploads: theater files are a LOT smaller than video recordings
Reported hackers go directly to Ban Candy
(To keep you hosting servers clean of hackers, simple kick/ban IP from accessing you as host)