So for a while we've been suspicious why seemingly so many ships have random sets of wrong photos in them. There's just no way so many photographers upload their photos for the wrong vessels. At this point it's pretty clear something is wrong on our end.
Sometimes ships change their MMSI (this usually includes owner change, name change, flag change etc.). This will cause our system to create a new page for this ship, since it can't know it's technically another ship in the database. This would cause a sort of loss of data (photos, tracks etc.). To avoid this, our system tries to identify those "new" ships and tries to merge the associated data into one ship in the DB. It does this by using the IMO number, which sticks with a ship forever. In 99.99% of cases this works fine. But it seems like the data from ships' AIS transponders is not as reliable as we thought, too many times incorrect IMOs seem to be entered or transmitted, causing our system to merge the wrong ships.
For now we disabled this merging of data to investigate how to further handle this situation and how to restore photos to their correct ships.