Ever wonder why no one has challenged it since?You do realize that a federal court struck down the NFA provision against SBSs in the 30s? The .gov appealed it to the SC and got the conviction reinstated and the ruling against the law overturned when the owner of the SBS in the case failed to appear leading to a default judgment with no consideration being given to the fact that the man had not been informed of the SC case or the fact that he could not appear by virtue of being dead by that time.