“Speeding Anacdotes”

So here's a question, regarding things I've seen on line.

"My car can do this... my car can do that.... my car can beat yours.... I took my car up to xxxkmph on the highway"

So let's say you admit to speeding and let's say it was a very HIGH rate of speed in order of magnitude.

IF the person posting the comment and speed and "could" be traced identified,

could the person be charged and successfully prosecuted?

Let's say the person could NOT be successfully be ID'd but the speed was dangerous, or the person continued to brag about multiple

speeding, would a LEO department actively try and trace the driver, or would they need a complaint,

I'm not talking about say, mass cruises, club meets or racing.

Just a single individual out hooning in his or her car

In other words is it an admission of guilt (without evidence)

I a couple of youtubers have got caught and successfully prosecuted, but that's because they posted on line there "actual" speeding videos.

But what I am talking about, really is "bragging" rights?