If you have read the law or this linked github page you have seen that security was considered, search for this text
The processing of personal data to the extent strictly necessary and proportionate for the purposes of ensuring network and information security, i.e. the ability of a network or an information system to resist, at a given level of confidence, accidental events or unlawful or malicious actions that compromise the availability, authenticity, integrity and confidentiality of stored or transmitted personal data, and the security of the related services offered by, or accessible via, those networks and systems, […] by providers of electronic communications networks and services and by providers of security technologies and services, constitutes a legitimate interest of the data controller concerned.
Did you read this and it was not enough for you,
Btw is DDOS and not DOS attacks (in case it was not a typo)
The processing of personal data to the extent strictly necessary and proportionate for the purposes of ensuring network and information security, i.e. the ability of a network or an information system to resist, at a given level of confidence, accidental events or unlawful or malicious actions that compromise the availability, authenticity, integrity and confidentiality of stored or transmitted personal data, and the security of the related services offered by, or accessible via, those networks and systems, […] by providers of electronic communications networks and services and by providers of security technologies and services, constitutes a legitimate interest of the data controller concerned.
Did you read this and it was not enough for you, Btw is DDOS and not DOS attacks (in case it was not a typo)