Actually, even if you did file all your AR-11 notices, there's no way you can prove it -- USCIS does not send you a receipt saying it received your AR-11. You claiming you filed an AR-11 vs. the USCIS saying they didn't receive it, doesn't say a thing. This is why I have a hard time believing some of the things in that NY Times article.
I have a Fedex signed delivery for the person at USCIS London Kentucky who recieved my AR-11 updating my latest address. I hope this will help in case he asked me about filling AR-11.