One could also adjust the scripts to stop. Again, from the man page:
A common system administration error is to delete the links with the
thought that this will "disable" the service, i.e., that this will
prevent the service from being started. However, if all links have
been deleted then the next time the package is upgraded, the package’s
postinst script will run update-rc.d again and this will reinstall
links at their factory default locations. The correct way to disable
services is to configure the service as stopped in all runlevels in
which it is started by default. In the System V init system this means
renaming the service’s symbolic links from S to K.
One could also adjust the scripts to stop. Again, from the man page:
A common system administration error is to delete the links with the
thought that this will "disable" the service, i.e., that this will
prevent the service from being started. However, if all links have
been deleted then the next time the package is upgraded, the package’s
postinst script will run update-rc.d again and this will reinstall
links at their factory default locations. The correct way to disable
services is to configure the service as stopped in all runlevels in
which it is started by default. In the System V init system this means
renaming the service’s symbolic links from S to K.