@RottenDennis,
We've had the bot invasion since at least last May. There are tip-offs that one is dealing with a bot, some subtle, some pretty damned obvious. I never describe those in a post, though, because i don't want the bot creators to know what the telltale traits are.
There are other spammers, or perhaps their bots, which do key word searches and the post in threads about a specific topic. So, for example, in a thread about a particular contemporary movie, people we've never seen before (and likely won't see again) show up to praise the movie. Most of them are rather obviously not native speakers of English, and i suspect the source is India, where many people who don't speak English well think they do.