Looks like the original listing has already been taken down.
The Common Acess Card (CAC) was implimented in the U.S. Military not long before I retired. I'm also quite familiar with how it looks from a civilian DOD employee perspective as well, since I work for a naval shipyard as a civilian DON employee.
Here's some information which points to the ID card being fake, for those who are interested:
The picture is not in the right format. The image is not cropped the same way that CAC images are. It's too wide for it's height.
If you were to look at the person in the image closely, the shoulders don't look like they're correct for someone who is standing at ease in front of a camera being operated by another person. They look typical of someone taking their own picture. (My opinion, here.) I'm not sure what's shown on his right (???) shoulder...I'll leave that for someone else to critique. But ID pictures don't commonly include enough to show any ribbons, medals, or insignia that isn't a collar device.
Pictures on CAC's don't have the U.S. flag in the background. It's a plain background.
"ACTIVE DUTY" is in all caps. The military has long since gotten over the caps lock handicap and this is printed as "Active Duty" on all active duty military CAC.
The name is also in all caps. Again, the military doesn't use all caps for this. It should read "Danielle Gamache" for his first and middle names.
The Pay Grade is not correctly annotated. Enlisted people are annotated by "E" with a number afterwards, indicating the enlisted paygrade. For Sargent, this would be "E5". "OF3" appears to be completely nonsense, since officer's are shown with the letter "O" followed by a number and Warrant Officers are shown with the letter "W" followed by a number.
The "Pay Grade" and "Rank" lettering and the grade and rank shown are of incorrect font sizes, relative to each other.
The Issue Date and Expiration Dates are inconsistent. The Issue Date is the date the ID card is issued to the servicemember, not the date he enlisted. New ID cards are issued whenever there is a change a change in rank, enlisted obligated service dates, or whenever the card is damaged or lost. Enlisted contracts are for a maximum of 6 years. Note that this has nothing to do with the minimum required service time one is obligated for...only that the maximum term for any enlistement period itself is 6 years. The maximum period shown on the CAC can be no longer than the date it was issued to him to the end of his active duty obligated service. Thus the maximum period shown cannot be any longer than 6 years. The time on this ID card shows 9 years from the Issue Date.
The "Issue Date" and "Expiration Date" and the dates shown below them are the incorrect font sizes, relative to each other. See the CAC website to see what I mean.
http://www.cac.mil/common-access-card/
The vertical bar code shown does not look like the correct barcode format. Visit the Common Access Card website to see what one is supposed to look like.
All CAC's have that wavy background image/lettering on them in green lettering. Mine says "U.S. DEPARTMENT OF DEFENSE" in all caps. Likely they all have this, since the branch of service is clearly annotated by the branch seal in the upper right corner and the name of the service clearly printed below that. But it's currently 5 am where I'm at and I don't feel like running down to the waterfront to find a Sailor on duty and ask to see his CAC to verify that.
The ICC (Integrated Circuit Chip) contacts are an electronic image, not a real picture of one. The image shown has a "reflection", a bright clash across it. Yet the rest of the shiny plastic card does not have that. The contacts shown aren't what they're currently shaped as on the real thing, either. As shown, a CAC with this ICC contact configuration would not function in a CAC reader, and these readers haven't changed functionally since they were introduced.
And finally, the "picture" of this CAC is not, in fact, a picture of a CAC at all. A real CAC is a credit card sized and shaped ID card, complete with edges and rounded corners. This picture, even if it is a cropped one, doesn't show that. There is absolutely no hint of the wavy background security lettering. As measured, the aspect ratio of the card is incorrect. The card is slightly too short for it's height.
I hope enough heat has been delivered to the proper authorities to have the hammer dropped on this individual. I don't cotton to people impersonating servicemembers, especially for nefarious purposes. And if he's current or prior military, I don't cotton to liars and frauds.