A whitehat hacker from the Baltimore suburbs went too far in his effort to drive home a point about a security vulnerability he reported to a client. Now he’s unemployed and telling all on reddit.

David Helkowski was working for Canton Group, a Baltimore-based software consulting firm on a project for the University of Maryland (UMD), when he claims he found malware on the university’s servers that could be used to gain access to personal data of students and faculty. ...