Webhosting : Control panel written in php security question

When people register an account, a folder will be created for the user, and will be named with his/her username. However this folder will be owned by the linuxuser “http” since pages will be uploaded by people via a control panel written in PHP. So folders allocated to users, and any file that gets uploaded via the control panel will all be owned by the linuxuser “http” with permission 755.