Those are licensed and regulated. And I am pretty sure that if FAA sends you a notice to stop flying your weather balloon, you stop flying it. It’s not like this “pilot” didn’t know what he was doing - he received written warnings and chose to ignore those.
This is not true, as for certain weights of payloads are regulated, all these 'near-space' hobbyist balloons do not need to notify the FAA about anything. It's common courtesy to let them know you are going to send something up to 120,000' but not required.
Any one of the following payload conditions trigger these restrictions:
- more than 4 lbs and more than 3 oz/in² on any side
- more than 6 lbs
- two or more packages totaling more than 12 lbs
- suspended from a rope or other device that requires more than 50 lbs to separate
So you’re right; small payloads don’t require any notice or special equipment.