Several weeks ago I saw several different radios for sale, all were allegedly from different people. I was thinking of buying one of the radios but decided against it. As I looked at some other radios that were posted within a few days of each other I found a few listings that I suspected were written by the same person. What tipped me off is that the sentence structure in all the ads was stilted. Managing an import business, I see these mistakes daily which is why it's my opinion that he or she is not a native english speaker. (My guess is a former Eastern Bloc state). Issues I noticed were the incorrect use of tense and verbs. It wasn't widespread misuse -- which is why I almost overlooked it. And I'd probably have overlooked it were just one ad; but three ads from three different people who made the same uncommon mistake made me suspect a problem. There was also one more grammatical "fingerprint" common to the three ads that I noticed when I looked at them deeper - which to me confirmed that it was the same person. To catch this person, my suggestion is to first analyze the ads that were scams. Look for the common grammatical errors. These errors will continue to occur and will make it easier to find suspect ads. If anyone still has access to the ads that have turned out to be scams, analyze them deeper and you'll see the fingerprint I'm talking about.