As I understand it, the majority of junk is 1. 480 million copper pins the US military put into orbit[0] and 2. 150k pieces of junk from the Chinese anti-satellite weapon test/demonstration[1].
So if we're going to charge someone for this, first and foremost are the US and Chinese militaries.
Thanks for linking to the interesting story, but it doesn’t agree with your comment. Wikipedia says there are only 36 clumps of needles left in orbit.
Good catch. I didn't fully reread it before posting. I was also unsure if the individual needles were still around, but the article says they'd have decayed after ~3 years, so it's just those few clumps that are relevant.