  Registering periodic variations of spectral line widths serves as the main
method for observing torsional Alfv\'{e}n waves. Theoretically, the method
seems valid, yet it entails a number of caveats when applied to data. For
instance, the amplitudes of these observations should vary with changes of the
location on the disk, and they should be associated with no intensity
oscillations. We analyze extensive observational material of periodic
non-thermal variations of line widths in coronal holes and facular regions in a
number of spectral lines: H{\alpha}, He I 10830 {\AA}, Ca II 8542 {\AA}, Ba II
4554 {\AA}. In most cases, we detected associated intensity oscillations at
similar frequencies. Besides, we observed no centre-to-limb dependency. This
calls for a discussion on the practical validity of the method and on the
alternative explanations for the nature of non-thermal variations of spectral
line widths. Based on our observations, we consider registering line profile
broadening a necessary but not sufficient means for unambiguous identification
of torsional Alfv\'{e}n waves in the lower solar atmosphere.
