All user-contributed content on Stack Overflow is under a CC-BY-SA license. So what the sites are doing is allowed under the license, as long as they're providi

All user-contributed content on Stack Overflow is under a CC-BY-SA license. So what the sites are doing is allowed under the license, as long as they're providing attribution. Is it annoying? Sure. But neither Stack Overflow nor the authors of the content can do anything about it since they gave away a license to do it. One of the things you have to accept when you release something under an open-source or Creative Commons license is that other people can take it and use it in ways that you don't like.