To put it in plain English, Twitter might eventually be the tool to determine nightlife activity, which has been a traditional blind spot where urban planning is concerned. To cite an example, the researchers have come up with a trio of case studies which involve Manhattan, London and Madrid, where they found out that Madrid had more evening Twitter activity in the weekends, while those living in Manhattan tend to spend more time out at night during weekdays. London, on the other hand, obtains more tweets during the daytime, and majority of it would be in leisure areas.
This data, if used correctly, could come in handy to figure out the exact place and time to allocate valuable city resources including security and cleaning, not to mention dealing with perennial issues such as noise pollution. This is still an idea that is in its infancy, so it remains to be seen how all of it will pan out eventually.