Around 60 of those will have been search bots. They visit regularly - if they're from a big name like google, they arrive in packs.
This has come up before. People tend to forget these things though unfortunately, and expecting new members to read every guide or policy when they sign up is quite silly because as we all know it never happens.
The moderators usually deal with mis-placed threads quite quickly, so I'm not sure this is a big problem. Usually if people aren't sure they will post in "General Science", and if there's an obvious category for that thread it will be moved quite quickly.