How do I avoid my ~/.kde/tmp-sda2-enc/.kio_thumbnails* using all my free space

[user1]

>>
>> I have even tried following command
>> rmdir --ignore-fail-on-non-empty /home/username/.kde/tmp-sda2-enc/* but
>> the empty directories will still not go away.
>>
>>
> 
> rm -R <dir>
> rm -Rf <dir>
> 
> hidden files?

It worked, but I had to do it as sudo, strange as you should not have to 
use sudo for your home dir?