Summary
This proposal reduces the MKR market's borrow limit from the current value of 25,000 MKR to 5,000 MKR.
Reasoning
Lowering the borrow limit makes it more difficult for malicious parties to interfere with MakerDAO governance. This should reduce the likelihood of disruption to Compound's DAI and MKR markets, and also minimize risk to the wider defi ecosystem.
MKR is not frequently borrowed, and based on historical demand across Aave and Compound this 5,000 token limit is unlikely to limit typical usage.
See the full discussion here.