https://community.ccleaner.com/t/ntfs-compressed-files-are-not-securely-deleted/13903
NTFS compressed files are not securely deleted - CCleaner Windows Bug Reporting - CCleaner
May 31, 2008 - CCleaner seems unable to overwrite files that are compressed under the NTFS file system. Usually, if I clean a large amount of data, CCleaner will take a while...
ntfs compressed filesbug reportingsecurelydeletedccleaner