Our results for one particular benchmark do not rule out the possibility of speedup for other classes of problems and illustrate that quantum speedup is elusive and can depend on the question posed.
The study asks a very specific question and acknowledge its limited scope.
Imaging through scattering media, for noble causes such as medical imaging, is a current and productive research area in optics. You can account for essentially arbitrary scattering as long as it doesn't change quickly. While the technology would be different, but I expect that the mathematics and the techniques already exist to thwart and such wall which you might design.
On the other hand, a 5mm sheet of aluminium ought to do the trick.
Three of the British warships sunk in the Falklands war
Physics World has a slightly more in-depth article.
Nothing will ever be attempted if all possible objections must be first overcome. -- Dr. Johnson