Today I read Official EU Agencies Falsely Report More Than 550 Archive.org URLs as Terrorist Content. Two comments on this.
1. It happened to me in Feb 2019. I archived one of my stories from the chemical sneakernet universe. The original story is posted on telegra.ph. Here is the message which appeared when I checked the archived link:
What? I contacted archive.org and got an answer from the webmaster, pretty fast. The problem was with telegra.ph, not with my link in particular. Now the archived link is available.
After I sent the message to archive but before I received the answer, I searched for a way to contact EU IRU, to ask what the problem might be. I was unable to identify any such way. However there was a way to send a message to EU officials, who might redirect my message to whom it may concern. It worked, but it took longer than the time needed by archive webmaster to respond and unblock the link. I was not contacted since.
2. As you see in the post from archive, it was not EU IRU the institution which sent the blocking orders. But nevermind, how can one try to block arXiv articles? This reminded me of a very recent story: Google Scholar lost my Molecular computers arXiv article. As the article is on the same subject as the story from point 1, I wonder if by any (mis)chance Google Scholar received a blocking order.