For those -- like me -- wishing to get rid of this "pollution" in the user directory (apparently caused by a lightdm bug described in Why do I have so many .Xauthority.* files in my home directory?), an interim solution could be placing something like the following (executable) script file (which assumes you are the first user after root) into the /etc/cron.daily
directory:
#!/bin/bash
USER="$(users | awk -F ' ' '{print $2}')"
ls /home/"$USER"/.Xauthority.* > /home/"$USER"/.Xauthority-Files.txt
NFILES="$(grep -c Xauthority /home/"$USER"/.Xauthority-Files.txt)"
LOG="/home/"$USER"/.Xauthority-Files.log"
echo -e "$(date +"%x %R"): "$NFILES" .Xauthority.* files deleted" >> "$LOG"
rm -f /home/"$USER"/.Xauthority.*
rm -f /home/"$USER"/.Xauthority-Files.txt
exit 0
NOTE: This updated script keeps a log file named ".Xauthority-Files.log" so that you can follow up if a recent update has put an end to this bug, and then remove the script when it's no longer needed.
.XAuthority
file.