nostr:npub1n0sturny6w9zn2wwexju3m6asu7zh7jnv2jt2kx6tlmfhs7thq0qnflahe What are these white triangle symbols with an exclamation mark that populate the feed suddenly?

https://cdn.nostrcheck.me/e417ee3d910253993ae0ce6b41d4a24609970f132958d75b2d9b634d60a3cc08/6077f12b11eaa4267f75976dfc279e0d94a4324e939fe4908dd3a3cce6fc1690.webp