.Trash-0 is a locked hidden folder in Ubuntu /home. There were quite a few MB worth of files which I deleted. I hope this is safe. I am not sure what the idea behind this location for trash is, as there is the trash can (recycle bin) plus the /home/user/.local/share/Trash folder which I also empty from time to time. I think files go there if one deletes something with root permissions. I don't understand the purpose of the .Trash-0 folder. Edit:- Maybe the files in .Trash-0 were due to having transferred them from a DVD/CD which had backed up stuff from my old Windows XP OS ? Is that possible ?