On Monday, I opened my Flickr photo account to find that over 900 of my 1800 images had been deleted. It happened some time in the prior two weeks. Some photos had been replaced by offensive images related to my benign photo titles so, clearly, it was vandalism. For various reasons, among them the fact that I use 2-step authentication, I don't believe the vandal got into my account through the front door using my password.
Last night, I opened my Flickr account to do further damage assessment and begin the restoration process. No need. Everything was fixed. The offensive photos were removed and, best as I can tell, all of my photos were recovered. I assume the hack was on Yahoo-Flickr's end, and I guess they caught it and restored my images.