TL;DR: every day, there are hundreds of wrong URL requests being done due to memory failures in the computers. Due to hardware problem, the computer can connect

TL;DR: every day, there are hundreds of wrong URL requests being done due to memory failures in the computers. Due to hardware problem, the computer can connect e.g. to microsmft.com instead of microsoft.com. The data gathered by the researcher suggests those kind of bugs happen also in web caches etc. thus increasing the number of affected users. In practice, the privacy problems coming from this are rather limited (unless you send private stuff in URL), since in majority of cases, you'll not be sending domain cookies for the original domain if it resolved to the bitsquat domain early. Anyway, it's still probably a thing not thoroughly thought of on a daily basis regarding security.