While it is true that online research can help to better understand the person you are meeting and can be an important tool in making sure someone is who they say they are, there are limits to what you can and should do. For example, it is never appropriate to go too far into someone’s personal life and to invade their privacy. It is also inappropriate to use this information in a malicious way or to make assumptions about someone based on what you find.
Additionally, it is important to remember that Nikhil's original essay focused on situations when you already know something about someone but can't reference it because they wouldn't like that you looked them up online. This is different from researching someone before you have met them, as Nikhil never suggested that all online research should be avoided.
Ultimately, looking someone up online can be useful in some situations, but the practice should be taken with caution and consideration. An appropriate level of research can be beneficial, however invading someone's privacy is never acceptable. It is wrong to assume that Nikhil was promoting an “anything goes” approach when it comes to online research - he was simply making a point about the need for caution when you know something about someone which was learned through online research. After all, no one wants to be labeled as a stalker!