Ah yes I noticed that too. So basically for me my node is duplicated 17 times (just check bangkok, Thailand on the map).
And that's the result of how rmap.world functions: they list what they discover that claims to be at position X (since location is something you can manually specify). It doesn't even have to be 'real'. The way they handle this is by disapearing the nodes that didn't announce for 7 days, but it's not a good solution IMHO.
It doesn't require you to be operating a propagation or transport node: they just discover everything that's discoverable and has a location, then print it. As @welo says, if ANYTHING changes, it will add another marker for that exact location.
They need to update this for 2 reasons:
a) if my IP changes, which it does because my node isn't fixed, and i'm not using a dyn DNS, a new instance spawns. That's regardless of the "reachable_on=", which i left fixed but has no correlation to reality anymore. I find that weird but yeah everytime i move networks, a new dot spawn.
b) needless to say anyone with a python script could paint the map in about 5 minute flat by spooling up fake instance.
My config if you are curious:
[[My Node]]
type = TCPServerInterface
enabled = yes
listen_ip = 0.0.0.0
listen_port = 4242
discoverable = yes
discovery_name = TEST_NONGKHAEM_BKK_TH
latitude = 13.683419053492303
longitude = 100.35779615497232
mode = gateway
discovery_lxmf_address = e23e9a470d42f05d8e5f94c222caf723
discovery_stamp_value = 22
reachable_on = 27.130.2.74