The unbreakable umbrella is your best bet for a SD choice that can be reasonably carried and that won't get your peers thinking you're weird (a la walking for a cane).
Situational awareness is indispensable, because if you simply APPEAR aware and are able to duck, run, evade, etc, you will not be seen as an easy victim. I'd bet dollars to donuts those 3 people were all oblivious before being attacked/robbed/etc. They were probably drunk, on a cell phone, texting, looking at the ground, or whatever. I know you were posting that as an illustration to say why you're worried, but I wouldn't worry much. The easy prey will get targeted. If you don't look like prey you likely won't.
It's amazing what making repeated, confident eye contact as your proximity to a potential threat increases will do. If you look confident/prepared you can walk right by someone who was initially thinking of victimizing you. Now, I'm not saying you should allow such a person to get close - I'm saying you should make confident, aware, obvious eye contact (and watch hands/waist line, body language etc) from say, 30 yards, 10, and 5. Not in a rude/staring or scared way, nor in a threatening way, just a confident and justified way - you have every right to assess your surroundings. IF you can pull this off confidently with every person you meet, you are way less likely to be targeted, and if you are, you are more likely to see it coming.
Situational awareness is indispensable, because if you simply APPEAR aware and are able to duck, run, evade, etc, you will not be seen as an easy victim. I'd bet dollars to donuts those 3 people were all oblivious before being attacked/robbed/etc. They were probably drunk, on a cell phone, texting, looking at the ground, or whatever. I know you were posting that as an illustration to say why you're worried, but I wouldn't worry much. The easy prey will get targeted. If you don't look like prey you likely won't.
It's amazing what making repeated, confident eye contact as your proximity to a potential threat increases will do. If you look confident/prepared you can walk right by someone who was initially thinking of victimizing you. Now, I'm not saying you should allow such a person to get close - I'm saying you should make confident, aware, obvious eye contact (and watch hands/waist line, body language etc) from say, 30 yards, 10, and 5. Not in a rude/staring or scared way, nor in a threatening way, just a confident and justified way - you have every right to assess your surroundings. IF you can pull this off confidently with every person you meet, you are way less likely to be targeted, and if you are, you are more likely to see it coming.