You're right, I'm sorry. I don't think your idea is a good one. For some reason, I think that if your county is getting bombed, then a shirt like this would be a good idea, because the bombs can not be 'aimed' at one person. If you wear one of these shirts in front of the sniper, you are just asking for it. The first person with one of these shirts to get hit would instantly make the remaining shirts dust rags.
If this guy has you in his crosshairs, which is probably several minutes before he actually shoots someone, you think he would pick you because of the shirt? This seems as likely as being the one to get shot by the sniper.