In the recent past, various established certification service providers (CSPs) regarded as trustworthy by browser manufacturers have been attacked and in at least two cases (Comodo and DigiNotar) also compromised. The attackers succeeded in issuing bogus SSL/TLS server certificates with which large-scale man-in-the-middle (MITM) attacks were carried out. As part of this technological consideration, we will show what happened and the ramifications the attacks may have on the design of current and future public key infrastructures (PKIs).