Hi ! =)))
Your discussion made me recall, this ‘c’ usage comes from the use of the place one is from as used in the Ukrainian, e.g. the Russian would say, “Он - из Киева”, whereas the Ukrainian would nearly always say, “Он - с Киева”, both meaning, “He is from Kiev” (the capital of the Ukraine).
Besides, whenever you’re speaking in Russian of being from any island state you nearly always would use ‘c’, e.g. “I’m from Cuba” - “Я - с Кубы”, “I’m from the Philippines” - “Я - с Филиппин”, etc.
But, please, notice, when talking about peninsular state in Russian, the usage is rather arbitrary, e.g. you may say in Russian, “I’m from California” as both “Я - из Калифорнии” AND “Я - c Калифорнии”; these two being both absolutely acceptable.
The slight difference is the implication, but I emphasize, it’s only SLIGHT and not even necessarily implied in each case, but still, if you are about to further specifiy the city in California you are from, you’d most probably say, “I’m from California, from the city of …”, i.e. " Я - из Калифорнии, из города …", but if you do not have any disposition at all to get into further details, you will surely restrict yourself by saying, “I’m from California”, i.e. “Я - с Калифорнии”.
Again, I’d like to emphasize, the choice is VERY much arbitrary, i.e. you are in NO way compelled to use one version once you feel like getting into further detail, and not to use another one if you are not. =))
Notice: Both punctuation versions are acceptable, i.e. the one with a dash indicating the missing verb (am) which was used in ancient Russian, and without any dash at all, the former version implying ‘As for me, I’m from California’, whereas the latter one is just a neutral declaration of the fact, i.e. “I am from California.”