Normally a user can use the ps command to see any process running on a system.
A nice additional security measure is to hide these processes.
A user may be able to "see" only her own processes thanks to the security.curtain sysctl option.
Run following command as a user with root privileges:
# sysctl -w security.curtain=1
Now type as normal user:
# ps auxww
You should be able to see only processes belonging to your user.