System designed for different addresses

AVS was designed to take advantage of the 9 digit zip codes used in the US which pinpoint down to about a block in most cases combined with the larger 5 digit house numbers that are also often used. That would have meant that a typical house will only share its AVS code with 1 or 2 others in most cases. The problem is people don't seem to remember their 9 digit zip code and tend to remember just the 1st 5 so the zip+4 was dropped. Aussie banks (except Citibank) are going with the excuse that AVS violates privacy so they refused to even do these trivial checks.