I'd be pissed. I work hard on my content, that ad revenue is mine, not some asshole who just screenshotted my pages and reuploaded them.
I've had some pieces of content go viral in the past that I posted free online and seen them get millions of hits on sites like 9gag that have ads. Like it's possible you've seen this meme going around Tumblr or Facebook over the years:

I MADE THIS. I have made no money ever from this, and I can only wonder how much the sites it was reposted to made off it, because I know it got literal millions of hits on 9gag alone. Worse, I made it at a time in my life where I was financially really struggling and could have really used the money. I've seen this design printed on t-shirts and merch, shared around social media, used as an image on professional blogs... It's like everyone's making money off it but me, the person who made it. So yeah, I don't find reposting flattering. It's annoying and exploitative, because the people profiting from reposting are practically always way better off than the people who poured heart and soul and inspiration into the actual content.