Allot Communications blocking of vanilla Tor, obfs4, and meek in Kazakhstan, starting 2016-06
At the beginning of June 2016, direct users in Kazakhstan fell, while bridge users simultaneously rose. Thereafter, bridge users slowly declined.
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The mainly used transport was obfs4.
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The dip in bridge users during September was likely not related to anything happening in Kazakhstan, but is an artifact of the changeover of bridge authorities. See https://lists.torproject.org/pipermail/metrics-team/2016-September/000217.html.