DHS or someone will be coming after him. Count on it.
Is there anything with launching a weather balloon into an area where there may be air traffic... only if lots and lots of people start doing it.
If it had been in the vicinity of Charlotte NC...you betcha...they’d already have orange prison suits and prisoner ID #s.
Some rules, but they seem to allow smaller balloons -
http://www.eoss.org/pubs/far_annotated.htm
If you keep it small, the rules may not apply.
After WW-2 a friend and i bought a weather baloon at the war surplus.
We filled it with hydrogen we made with zink and Hcl, made a long fuse with gun powder and string and glue.
We set it off just about dusk durring rush hour.
I blew up at about 5,000 ft.
It broke a few windows but motorists flooded the cops with calls.