A few years back or so, there was a guy on the India subreddit desperately asking around if anyone saw his relative (I think uncle or brother), who had autism quite visibly, and had gone to the railway station of his own accord. Even though the police were quite actively involved, which is unusual in India for the most part, I don't think they were able to locate the missing person. If such tracking can prevent situations like those, then I'm fully in support of those measures. The key word here being consent of the individual.

Edit:- The uncle was found fortunately, severely malnourished and living on the streets, after almost 5 months.

https://www.reddit.com/r/india/comments/80ubg8/need_help_my_...