Habr question - hi_flow cookie?

Question

Habr

Literally half an hour ago, on all pages of Habr, it began to give out a 404 error (the one with the planets).
Friends said they were fine. I checked in another browser - everything turned out to be fine too.
Then I deleted the cookies and, lo and behold, everything was fine too.
I re-entered Habr and again planet 404.
I decided not to delete all cookies, but only delete the incomprehensible hl_flow and everything worked again, and the authorization is fine.
Cookie returned later, but everything works.
What is this joke?

Answer 1

This is the last tab you had in the feed. If you close Habr on it, and then open it, then it will open again.

Answer 2

Looks like DDOS protection

Answer 3

So it seems to be "repeating" horizontally, it's hard to see here, but it seems like it can be cut out.
Something like this:
Well, then just in css on div
Cut out the desired piece, depending on where you need to start, from an empty (white) point or from a circle, well, that is, you just need to mirror my area if you start from an empty point necessary.

Answer 4

With div:after ?

Answer 5

with background and background-position in body :)

Answer 6

Not worth it, too many elements will be added to the house. Older browsers will immediately start to slow down.