being delivered to teenagers on instagram because the algorithms learn correlations, where your party ad may still go to kids interested in partying because facebook is almost certainly has a ranking model in the background that it says this person wants more party related content. >> interesting. thank you. that's very helpful. what that suggests to me is that while they are saying they're not targeting teens with those ads, the algorithm might do some of that work for them, which might explain whey cy they coll the data. >> i can't speak to whether or not that's the intention, but it's very, very difficult to understand these algorithms today and over and over and over again, we saw these biases these algorithms they unintentionally learned. it's hard to untangle out these factors as long as you have en engaged based ranging. >> thank you very much.