CCleaner Warning
The program CCleaner is widely relied upon to delete unwanted files (such as internet .tmp files), and can also be used to overwrite unwanted files that you want to permanently delete.
Beware that version 5.45 and later of CCleaner may be sending user data to Avast the developer of CCLeaner.. See the particle posted here.
As reported by ZDNet, CCleaner sends user data back to Avast's servers. The CCleaner claims that it does not collect personal identifiable information but only uses anonymous usage data.