Deleting a file does not overwrite the data. It just marks that area of the drive as "free". Using forensic tools (or simply dd) you can read data from "empty" parts of the drive. To be save you have to overwrite each file. You can try tools like shred to scramble the data of a file before deleting it, but as they say themselfes, unfortunately your filesystem might not actually let you do that (scroll to the CAUTION section).
You can use dd to write bytes to arbitrary places of the drive, but again, the filesystem might lie to you where a file is actually located. The ONLY way to be entirely sure is to wipe the whole drive. And if your IT does not do that before handing a system to a new employee, then they are not doing their job correctly.
Not legal advice: just tell them you installed a few viruses (while the system was not connected to the company network of course) and they should nuke the system before handing it to anybody else.
(You can also wipe the drive yourself by booting from a stick and overwriting the entire drive)
... They can littetally not walk "freely". If they show interest in the wrong person they are stoned and burned exactly the same. Gay/Lesbians can also escape prosecution, they just have to hide who they are. Same as the BI person. Bi means beeing attracted to male and female and they have to surpress and hide that attraction or face persecution. That is not free.
A straight person how is persecuted for being attracted to anyone not called John/Jane isnt free just because there is someone they are allowed to be attracted to legally.