Good catch. That's a better quality backlink scam than we've seen in the past.
Do you remember the good old days of dumb scammers? They were so easy to spot. "I am great prince from Nigeria, and the bank want to give me my throne and 10 million US dollarses, but I am not has the $200 fee to claim up throne. Since I know that you JOHN SMITH, are an upstanding and trustworthy person, with many capabilities for great helping, I offer to pay you the sun of one million doolars next month if you just send the 200s of dollars to me bank account now"
If these people were smarter, and they will be eventually, using currently extant technology, they could replicate a live forum member that you couldn't detect. In fact, the only way you'll be able to tell a real person is that for a while, they will make less mistakes in forum etiquette than a real person.
Here's my suggestion, and it won't work for long, maybe just a year or two. Go into your site rules, posting guidelines, etc, and leave a dye pack for the robots.
Here's how it works. Add in a rule of conduct that's somewhat ridiculous, but vaguely plausible, like "to help others, please remember to be polite by including the model of your camera or filmmaking software at the end of each paragraph"
Most humans will either not read those posts, or will disregard that when they don't see anyone else do it. The early robots, for the first year maybe, will go and try to adhere to your community standards post, attempting to fully conform and become invisible in the process. So you can trick them into revealing themselves by adding one of these "dye packs".