When weaknesses are found in cryptographic protocols or algorithms on which the everyday security of the Internet relies, it is important that they are replaced by more secure alternatives. This is clearly emphasized by the recent case of MD5, an algorithm commonly used to create digital signatures in which severe weaknesses were found in 2004. The continued use of MD5 by several leading Certification Authorities (CAs) on the Internet enabled our team to become a rogue CA itself, triggering quick and adequate responses from the affected CAs and major Internet browsers.