I got this from bgpmon.
Detected new prefix: 18.104.22.168/17 Update time: 2015-11-12 07:18 (UTC) Detected by #peers: 16 Announced by: AS3786 (LG DACOM Corporation) Upstream AS: AS2914 (NTT America, Inc.) ASpath: 18356 38794 45796 23947 38753 45300 7713 2914 3786 Detected new prefix: 22.214.171.124/17 Update time: 2015-11-12 07:18 (UTC) Detected by #peers: 16 Announced by: AS3786 (LG DACOM Corporation) Upstream AS: AS2914 (NTT America, Inc.) ASpath: 133165 23947 38753 45300 7713 2914 3786
Why is the as-path so long here? Several ASNs in the path are just 1-2 hops away from AS3786. And that's what they did in traceroute originated from those ASNs. For example, AS23947 can reach AS3786 via AS3491.
It appears to me that this is some kind of traffic engineering effort to mitigate attacks (the prefix in question seems to have been null routed at the edge), possibly using BGP community to restrict the announcement to certain (geographical) peers. This particular prefix was never globally visible according to RIPE RIS (126.96.36.199/14 is globally visible).
And how did AS3786 make it happen? imo this is very difficult with BGP if other ASNs aren't cooperating.