That is true if you have the "Inherit access rights from Folders" option enabled on your cabinet. With this enabled, moving a document to a different folder will change the access on the document to match the ACL of the folder. In order to change access on a document in ND you would need to have "A" rights to the document. For example, if you had a folder that was restricted to only a certain person or group and you moved a document into it, that document would then be restricted. We would not want to give this ability to users that do not have "A" rights to the document. An option for you may be to disable folder inheritance on your cabinet. If you are not relying on access being applied at the folder level this may work for you.