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Of course that case will fail but for almost all cases if you know something like that you took x bus to work and then a week later you took one to the mall its
by Polylactic_acid 6y ago
Of course that case will fail but for almost all cases if you know something like that you took x bus to work and then a week later you took one to the mall its now possible to find all of their trips. For someone you know somewhat well its not hard to find 2 trips they took and then be able to find all of their trips.
- mulmen 6y agoOk, so two trips but not any two trips. It requires a lot more knowledge of the person. For someone you know well why would you even need to look at the data?
- Polylactic_acid 6y agoIts almost any two trips. Its the exception that two people take the same trip together. I can think of a handful of people I could eventually find 2 trips for who wouldn't want me to have their entire travelling history.
- harrisi 6y agoOne could trivially establish multiple trips that anyone with even slightly public social media has taken.
- mulmen 6y agoOk this is an interesting point. I can’t tell if this is a challenging problem or not. It’s probably worth trying an experiment.
- toast0 6y agoThe thing is, if you know enough trips to unmask them, then you can find out about all their trips in that dataset. As an employer, maybe I can find out an employee wasn't home sick when they said, but took the bus to a station that only serves a competitor's business. Etc.
- mulmen 6y agoThis is a really good point. I hadn’t fully considered the different ways you could know just part of someone’s routine.