Just imagine the crowd when someone actualy find it...
also, i don't think its manual placed... because this mean a finite source of material instead of a bigger source , let's say a whole planet...
Actually, I'm almost 100% certain they are manually placed (at least partially). The reason for this was in the most recent patch notes. There was a note about being able to recall the ship near crashed ships and barnacles.
The crashed ship this refers to are the manually placed, persistent ships referred to in local galnet news (morse code in Sol for example). These ships were considered settlements and required you to go 1.5km away before you could recall your ship. As this never happens with random POI's, I think it clearly indicates that the barnacles are manually and persistently placed on the surface of the planet(s), just like the crashed ships.
This, of course, makes it a lot harder to find because you can't just randomly cruise looking for POI's. You need to systematically scan the planets to find the ship, and this is HARD. Like really REALLY hard.
With Sol, we had the lat/long coordinates prior to the decimal point. It still took a group of people a significant amount of time to find the crashed ship.
I later tried on another planet with known coordinates and spent hours there myself without finding it. To clarify again, I knew where to look and I still couldn't find it.
I personally think it's a really poor mechanic to place something on a random planet in a random system in a random area of space (the latter being suspected, now confirmed). It'd be like finding a specific building on earth, from a ship flying 300m/sec, while not knowing where it is, and being unable to detect it from a distance... except that there might be 10s or 100s of earths to look for and you first need to find the right one.
I don't see how it'll be possible without at least getting planet name and a specific coordinate location or general area to look in. Planets are way too big and the way of scanning way too bad (if POI scanning was useful for this, it might be different, but it really isn't - too much crap POIs).