For 'im Internet surfen', why is it 'im' not 'ins'
I checked the dictionary of Internet, it gives to examples:
1. im Internet surfen
2. ins Internet stellen

My judgement here is: first Internet is Neutral, then it's Dativ here, so it should be 'ins Internet surfen' but not 'im'.

Does it make sense??

Question

For 'im Internet surfen', why is it 'im' not 'ins'
I checked the dictionary of Internet, it gives to examples:
1. im Internet surfen
2. ins Internet stellen

My judgement here is: first Internet is Neutral, then it's Dativ here, so it should be 'ins Internet surfen' but not 'im'.

Does it make sense??

Answer

No no, wait. Internet is neutral (das Internet), but you ARE in the internet, which is a state (hence dativ),  not a directed movement (then it'd be akkusativ). So 'in dem Internet surfen' is ok.
Same here:
'Ich gehe in die Schule' (akkusativ) means 'I'm going to school'.
'Ich gene in der Schule' means 'I'm going in (inside / within) the school'