If you have configured clam to scan uploaded files, but it is configured incorrectly or fails to run for some unknown reason, how should it behave?  If you choose 'Treat files like viruses', they'll be moved into the quarantine area, or deleted. If you choose 'Treat files as OK', the files will be moved to the destination directory like normal. Either way, admins will be alerted that clam has failed.  If you choose 'Treat files like viruses' and for some reason clam fails to run (usually because you have entered an invalid pathtoclam), ALL files that are uploaded will be moved to the given quarantine area, or deleted. Be careful with this setting.