Additional info: For business reasons, there are certain pages that need to be 'frozen' with no updates/publishing allowed. This would include any object dependencies(templates, components, etc). Currently, I don't know of any way to keep users from accidentally changing a dependency(or even the object).
Workflow will not help you here because you can still publish a page in workflow (it will just publish the previous non-workflow version).
There is no feature in Tridion security which allows you to prevent a single page from being published to a target (other than disallowing all publishing to that target or removing all access rights from the page; even then it might show up in resolve operations from the parent SG, components on it, etc).
If you want to go even further you might also want to prevent images that are displayed on the page from being changed (which is even harder because they are not independently rendered).
Considering the scope of the requirement (absolutely no changes must be made to a published item) I would consider implementing this as a deployer extension (so you lock your published pages and any binaries displayed on the page at the deployment side returning an error to the content management side stating items are locked for business reasons and are not allowed to be modified).