This problem affects many hundreds of thousands of “hill people” in Thailand. Several groups (incl. Akha, Karen, Lahu, Lisu, Hmong, Yao) have no identity cards and consequently cannot get passports, house registrations, drivers’ licenses; they cannot legally get married, open a bank account, get a formal job, or even attend public school; they are subject to arrest any time they venture out from their “hills.”
These are not all “illegal aliens”: most were born in Thailand; their ancestors may have lived in Thailand for many generations. One told me what obtaining an identity card would cost; I don’t remember exactly but it was very expensive by Thai standards, perhaps $3000 for a “fake” ID, or $25,000 for a “real” ID. (I’ve no idea what the difference is between the “fake” and “real” ID card — perhaps how high-placed the bribed official is?)