I always like walks with my dobies... One problem with 'gangs'...is that many of these gangs are composed of juveniles... and if you pull a gun on one in self-defense...you can picture the newspaper headline: 'Unarmed Child Killed by Frightened Jogger with Gun' . It doesn't matter to some folks if the unarmed child was pretending to have a gun and was part of a gang that did have a few guns... The gangmembers will be the eyewitnesses...and you will be having to put your word against their's... I'd go for screaming help into the cell phone ... but if you must jog... or walk in certain areas...I'd recommend jogging/walking with a well-trained dog or two and to carry a cellphone... A gun is a last resort.
Some situations are 'unavoidable' and the nasty thing about predators - is that they will catch you off guard!