sed: preserving permissions for ‘./sedV1DdTm’: Operation not permitted

When I run sed in a command, I gave these weird errors:
sed: preserving permissions for ‘./sedV1DdTm’: Operation not permitted
sed: preserving permissions for ‘./sedV1DdTm’: Operation not permitted
sed: preserving permissions for ‘./sedV1DdTm’: Operation not permitted
sed: preserving permissions for ‘./sedV7ZEli’: Operation not permitted
sed: preserving permissions for ‘./sedHCMYLQ’: Operation not permitted
sed: preserving permissions for ‘./sedgxuMSU’: Operation not permitted
sed: preserving permissions for ‘./sedV4jD3v’: Operation not permitted
sed: preserving permissions for ‘./sedfaEcks’: Operation not permitted


Although sed continues to do what it suppose to do. These errors only 

disappear when I use sudo.


The command I use is normal:
sed '/list/d' listt>list


which I appear to be normal if I use it alone. I don't think these are errors 
but bugs. What do you think?
-- 
Ooker.