I was going to sign it, I don't mind giving my Email address but can't see why they ask for full postal address.
Could it have something to do with multiple signatories . 200 Peter Jones's will each have a different address and avoid duplicates , maybe ? More likely to change email addresses than postal.
Or, simply anther way to collate information on each and everyone. They can have what they want when it's one more tiny hope for helpless creatures, at the hands of ugly humans.