For a lot of people, GMRS is primarily for emergency communication. These folks have their own repeaters with their own rules. They will, no doubt, welcome new users to join them provided they agree to follow the rules. Access to repeaters is usually restricted via privacy tones. If the privacy tone is missing or wrong you will not hear transmissions from the repeater and the repeater will not hear your transmissions. It is a good idea to perform a radio check when you first program in a repeater rather than finding out you set it up wrong when you try to respond to your first emergency. If anyone gives you a hard time about a radio check, arrange to meet them on a non emergency channel to discuss it.