The page says "be sure to identify yourself as a constituent, and give your mailing address for verification." Is there a technical/legal reason for this, or is

The page says "be sure to identify yourself as a constituent, and give your mailing address for verification." Is there a technical/legal reason for this, or is it mainly etiquette? I've donated to Franken in the past and much of my family still resides in MN but I'm in CA now. Is there any reason for me not to call? (Would it also be bad form to send a check with a letter saying 'cash-me if you reverse position' -- is this tantamount to the corporate donations that lead to such legislation?) (I'll be calling CA reps, too, but just curious about all this.)