Big harpoon is 'solution to space junk'

[cos dem]

2. It's not the big satellites that are the problem.

It's the bits that we can't track reliably, but are large enough to cause damage or destruction, that are the biggest threat.
We can move satellites to avoid other big satellites (assuming we know about them. Given the Iridium/Kosmos collision, maybe we don't know as often as we should). Removing defunct satellites is a good idea, but this isn't necessarily a 100% solution.