- Avoiding damage on flatbed scanners

  Most flatbed scanners have no protection against exceeding the physical scan
  area height.  That is, if a scan is attempted with a height that exceeds the
  height of the scan surface, the scanner begins making loud noises and the
  scan mechanism may be damaged.  Thus, if you hear such a noise, IMMEDIATELY
  turn off the scanner.

  Normally, the backend will ensure that the maximum scan height is not
  exceeded.  However, if your scanner model has not been tested yet this
  safety-guard may not work. Please report errors like this to the author of
  the backend or the sane-devel mailing list.

- Security problems with saned (SANE network scanning daemon)

  saned does not provide confidentiality when communicating with clients.
  If saned is exposed directly on the network, other users may be able to
  intercept scanned images, or learn passwords for connecting to saned,
  with little effort.  Client systems should connect to saned through a
  secure tunnel to the server instead.

  saned is not a trusted program and should not run with root privileges.