There use to be a time that a stalker of their intended victim had to put forth some real sweat effort in order to successfully pursue that stalking. Nowadays, stalkers more times than not, don't have to actively pursue their victims by physically following them on their feet or via a vehicle, or many other things of that basic sort; but instead, they can do all of their tracking and thereby their stalking, essentially by utilizing information that is available via social media sites such as Facebook or Instagram, or by a google search, SMS tracking, GPS, or similar, and in many of these instances, often, by basically taking on the guise of being a friend, the information flow to the stalker becomes readily available.
The massive advantage that today's stalker has is that the information that they are essentially able to freely procure is extremely accurate, and because it is so pertinent, this allows the stalker to get a very accurate picture of what their victim is or isn't doing, even in the present time, and often times pretty much to receive advance knowledge of where that victim is going. The stalker often has all of the Facebook information, the cell phone number, make and license number of the car being driven, background criminal information, knowledge of the current family situation, as well as the location of both work and home address, and so on and so forth.
All of this information, pretty much seems to be sort of legally okay for a given stalker to have, especially if it is considered to be essentially in the public domain. Of course, as always, actions taken by a stalker against an intended victim, are in many cases illegal, but that doesn't seem to be much of a deterrent to those that wish to commit those crimes, so that, if the stalker is able to commit what offenses that they are intending to commit, the victim will be the one to suffer from it.
It is well to remember also, that most stalkers know that with all of the hi-tech tools that are available, that if they are persistent enough and thorough enough, pretty much they will find vulnerabilities that will allow them to successfully exploit their victim. The problem that all of the potential victims have is that even if they are diligent in protecting their social media as well as other accounts, the very fact that they have those social media accounts makes them vulnerable, and the fact that publicly available information for individuals has been collated and processed by third party companies, all means that such is now available to just about anyone for a trivial price.
The reality is that we live in a hi-tech world, in which there are certain people that for whatever reason, do not have good intentions towards other people, that is, their intended victims; and basically through apps, their initiative, social media sites, and publicly available information, are able to stalk other people exceedingly well, often aided by the fact that they can assume the guise of a “friend” or a picture that doesn't represent them, and thereby ingratiate themselves further with the intended victim. This makes for a rather dangerous situation for the intended victim, caught between their usage of social media sites and smart phones, and too often unaware that those with evil intent are so easily able to stalk and to thereby harm them.