Were the modems in the original retail packaging?
It was in a brown box with Motorola printing on it, looked much like what a contractor would get. There was no shrink wrap. Had extra mmei/serial number stickers; although I cannot honestly remember if it was 'sealed' with tape or round labels. I confirmed it was brand new/never activated with my ISP. Way back when, I used to work for a cable company and it reminded me of the packaging we would receive our new equipment in. That being said, there is almost no way one could sell a lot of stolen equipment without getting caught up because of the mac/serial numbers.
I would highly recommend it. The seller has near perfect rating after a lot of sales.