Now according to the rules Habra to vote for topics and comments is possible only with karma greater than or equal to ten. As far as I remember, two weeks ago my karma, which is equal to 5, it was enough.
Actually a question: why the changes to the rules are announced in their respective blogs? I checked the blogs "Habrahabr" and "Habrahabr — announcements" and found posts about the changes in the rules. The question, of course, more to the administration of the resource, but maybe I was someone better, but I was wrong.