"Change your privacy-related settings"
Since version 0.9.8.2 (release notes).
This is necessary to be able to:
Disable "Prefetch resources to load pages more quickly"
This will ensure no TCP connection is opened at all for blocked requests: It's for your own protection privacy-wise.[1]
For pages with lots for blocked requests, this will actually remove overhead from page load (if you did not have the setting already disabled).
When uBlock blocks a network request, the expectation is that it blocks completely the connection, hence the new permission is necessary for uBlock to do truthfully what it says it does.
uBlock's primary purpose is to block network connections, not just data transfer. Not blocking the connection while just blocking the data transfer would mean uBlock is lying to users. So this permission will stay, and sorry for those who do not understand that it actually allows uBlock to do its intended job more thoroughly. A blocker which does not thoroughly prevent connections is not a real blocker.
Privacy Badger also requires exactly the same permissions. I want uBlock to also serve privacy-minded users first.
If prefetching had been disabled by default, this new permission would not be needed, but prefetching is unfortunately enabled by default, and under Privacy heading, which is itself hidden by default under "advanced settings".
Also, the benefits of prefetching are probably marginal, and in the context of a blocker, the benefits could be negative, since a lot of useless connections would be made, just to be discarded after the browser find out the requests won't be made anyway. So do not fall for the "lost of major performance boost" claim I read elsewhere, this is just a silly and baseless claim.
See code:
chrome.privacy.network