Not sure how long it will be posted there, but I found the link on the Drudge report.
REPORT: Feds send letters to vets taking away gun rights... It's in the first column, second article.
Which links to here, and subsequently to what was already posted from redflagnews.
I find this VERY hard to believe. Would love to see posts from individuals who have received the letter, not that I would wish it on them.