The gray man concept is one where you do not ‘advertise.’ This can be by stickers on your car, ham license plates, what you wear and what you post on social media.
With stickers on your car you can be giving away a lot of intel to an adversary. Of course, you can also gain a lot of information about your neighbors if you are doing your area intelligence correctly 🙂
Stick figure families are probably one that gives a lot of person information about your family composition. The age of your kids, and if combined with a school sticker, where they go to school. You tell people if you have a dog and sometimes if it is a threat or not (i.e., a small dog). If you are a single parent, and especially female, you could be indicating to potential kidnappers and child abductors.
NRA stickers tell people that you have firearms. Therefore your home could be a good target for those seeking weapons.
2nd Amendment, Gadsden, Punisher and gun club membership stickers also give away the fact that you probably have firearms, so again making your car and home a target.
Blue line and Trump, as well as 2A and similar stickers give away your political affiliation and in this current ‘charged’ environment will make your vehicle a target when parked but also make you a target if you get caught in a blocked road with protesters.
So consider ‘sterilizing’ your vehicle of stickers.
If you have a sticker for work parking ask them for a hang tag instead. Do not leave hang tags on your rear view mirror when not needed for access to work, again you are ‘broadcasting’ where you work.
Be careful of the pictures you post. First mage sure that the geo tags in your phone are off and not included on pictures. Any time you do an update to your phone go back in and check settings. In social media groups be careful how you answer questions, do not give away what you might have.
If you have a ham radio license consider using a post office box as your listed address. This is acceptable with the FCC rules.
It is also important that you do a walk around of your vehicle any time you have parked it in a pubic place to make sure that a marker or sticker hasn’t be placed on your vehicle to make you a target – this is especially important for females who could get targeted for abduction.