The law can't read your mind or intent, but the court can and will draw inferences from your observed behavior and in this case will almost certainly conclude that you are trolling. Why don't you try learning something about the how the law operates in practice instead of projecting your mechanistic conception onto it? I suggest
How Judges Think by Richard Posner, who's quite readable and probably the most widely-cited living legal scholar in the US.
Instead I will walk across everyone's property and if the police eventually stop me, I will say I intended to interview the homeowners but changed my mind.
For example, this might come off as a plausible argument if you walked up a few houses and then turned away, but the plausibility of your argument diminishes in inverse proportion to the number of property lines you cross without acting upon your stated purpose. You seem to think that judges live in some sort of vacuum which renders them incapable of applying common-sense standards or their own experience to the facts of a case. Now, this is arguably the case in some civil law systems - Posner offers an amusing example of a French law which made it illegal to disembark from a stationary train carriage due to a drafting error - but it's a far cry from how our common law system works or has ever worked.
Yet do it on a small scale to harass a single person and it is okay?
Here you're doing something called begging the question - you're assuming your conclusion as a fact. You consider unwanted journalistic attention to an individual to be harassment, and so you ascribe that as a purpose to the journalist. Think about it; the journalist isn't going to someone's house to make their life miserable, but in pursuit of information, which information may (or may not) be an object of legitimate interest. Finding out whether someone is the architect of a multi-billion dollar digital economy seems like an entirely legitimate subject of journalistic inquiry to me.