U.S. Code, Title 50, Chapter 32, Section 1520a -it's illegal for the military to - or contract others to -
"conduct weather modification experiments or anything that is capable of causing -
(1) death, disease, or other biological malfunction in a human, animal, plant, or another living organism;
(2) deterioration of food, water, equipment, supplies, or materials of any kind; or
(3) deleterious alteration of the environment.

without the prior informed consent of all human subjects.". . . . unless they just want to

''Conspiracy nonsense,'' snorts Kenneth Sassen, an
atmospheric scientist at the University of Utah. ''These
things are at 30,000 to 40,000 feet in the atmosphere.
They're tiny particles. They're not going to affect anyone.
The cloud-forming contrails that conspiracy theorists
find so ominous are perfectly natural. The odd grid and
parallel-line patterns are easily explained as contrails
blown together by the wind".

(Blow *this*, Ken)