Till Maas wrote:
The same people that provided the -1 karma can provide a +1 karma.
And
you only need have of these people to change their karma vote to get
back to zero karma. This should also not be a major problem, unless
there are people providing unjustified -1 karma to cause problems. But
you did not mention this.
People often provide well-meaning, but ultimately unjustified -1 karma. E.g.
we've often had -1 votes for regressions caused by some other package in a
completely different update or update set, or even for Bodhi or PackageKit
bugs which affect all updates and which don't affect the functionality of
the update in any way, just its display.
Kevin Kofler