It can be derived, which thousands of username in a single attack. It is one of the most dangerous threats on the web application's data theft at all at once.
It can be derived that the username is in the thousands, not a single attack. Making it one of the most dangerous threats on the theft of a web application ever.
It can make the acquisition of username thousands in a single blow. It is one of the most dangerous threats about stealing the information of web application.