Yeah, these things aren't unheard of but they would be an oddity and there isn't any single widely accepted method of programming one, etc. The Medabots thing is a big big anomaly because they weren't aiming to make them sapient like that and they were intended for public use, but I'd figure that the same thing would apply for any advanced AI that came to the attention of the authorities – they'd probably send people in to test the AI and check that there wasn't any kind of unethical abuse of a sentient artificial mind going on or whatever. So there are probably a number of less than scrupulous science guys building creepy sentient AIs who just aren't telling anybody about what they're doing in order to avoid getting their base of operations checked out – GLaDOS keeping her existence a secret would be pretty legit.