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The only services that should be affected by the use of such "bogus" addresses will be traceroute and any routing information passed by the device.

Unfortunately that's not quite true.

There are a variety of services which rely on messages received from intermediate hops that would break if the the sending host happened to filter out RFC1918 addresses and a part of the network were using them.

Probably the best example is Path MTU Discovery.

I meant "services used by normal humans in the course of downloading nude .gif's", i.e., typical Internet customers. I stand by my statement. :-)