“When I was debating the issue of eruvin with a poster on these boards, he made the ridiculous assertion that one person misusing an eruv makes it invalid for everyone. When I asked him to back up his statement, he gave me a very generic sounding name of a sefer for which he couldn’t provide an author, time/place of publication or anything else that could help me track down the source. Knowing more about the poster now, I’m again fairly confident that he made it up.*”
Because you couldnt find the sefer he made it up? Im ready to bet that hes right the sefer is real and the eruv is passul if someone doesnt use it write.