The use of flags from the German Third Reich (1933-1945) is currently subject to legal restrictions in a number of countries. Whilst legal in the overwhelming majority of countries, the display of flags associated with the Nazi regime is subject to restriction or an outright ban in others, particularly those with a direct involvement in the Second World War, and Germany itself.
The OP however is not about displaying Nazi insignia, but images of people and you can make images of whomever you like, but if you are making a hologram from someone else's photograph you might infringe copyright, but even so it would be almost impossible to make a case against an individual depiction.
The guy who's photograph of Che Guaviera has been reproduced millions of times, never could stop it, didn't make cent out of it.