I came up with a question to bring to the table:
Is it illegal for me to have a shoulder-holster instead of a waist-level belt holster, or a drop-leg holster?
Please see the attachment...
12025. (a) A person is guilty of carrying a concealed firearm when he or she does any of the following:
(1) Carries concealed within any vehicle which is under his or her control or direction any pistol, revolver, or other firearm capable of
being concealed upon the person.
(2) Carries concealed upon his or her person any pistol, revolver, or other firearm capable of being concealed upon the person.
(f) Firearms carried openly in belt holsters are not concealed within the meaning of this section.
That said I have seen many people using thigh rigs but always with an attachment to there belt as far as shoulder holsters go you might get away with it if it has an attachment to your belt and then again, they may say your arm was concealing it. I would not want to be the crash test dummy on this one.