It’s by Blockstream I think.

Raw JSON

{
  "kind": 1,
  "id": "4dc53eb9458a2cf834edb59a466a77a6084f0891b33407a7896e064371dc83ff",
  "pubkey": "079d727bee3d805e24758861ea4d028b2e6a37805f8db45bf8045bf900099650",
  "created_at": 1776307578,
  "tags": [
    [
      "e",
      "f6e43b3cc72f47f3c5373310ab66ff3f04c5012612eea9e58f1f2be18722ee6b",
      "wss://relay.mostr.pub/",
      "root",
      "a80fc4a78634ee26aabcac951b4cfd7b56ae18babd33c5afdcf6bed6dc80ebd1"
    ],
    [
      "e",
      "9161828d3b6280dba579f1f591ce5f109a5be8901f214ec065fd0a81714a4532",
      "wss://relay.damus.io",
      "reply",
      "a80fc4a78634ee26aabcac951b4cfd7b56ae18babd33c5afdcf6bed6dc80ebd1"
    ],
    [
      "p",
      "a80fc4a78634ee26aabcac951b4cfd7b56ae18babd33c5afdcf6bed6dc80ebd1"
    ],
    [
      "client",
      "Damus"
    ]
  ],
  "content": "It’s by Blockstream I think.",
  "sig": "a1ae7a096955e5bc2540d71d2fc18ba5d3bec0cfa2a64480b0138eeb9b1648f3f9661adce90890178fbba4349bad93da8281104c5c39ce30e83562f22b4510fc"
}