Security (b)log - English edition: June 2026

Image: Unsplash

They had just completed yet another cruise. This time too, they had managed to keep their feet dry, but as it turned out afterwards, there had been a leak after all. A data leak. And just like in the days of the Titanic, everyone acted as if nothing had happened.

They had not received a personal notification that their data had been exposed. They only found out by pure chance. In Europe, our first reaction is often to start waving the GDPR around indignantly: surely they have to tell me if my data has been leaked?! But it is not quite that simple. To begin with, the organisation responsible for the leak must determine for itself whether the incident has to be reported to the Dutch Data Protection Authority (AP). That is not required if “it is unlikely that the personal data breach will result in a risk to the rights and freedoms of data subjects”, as the AP explains. The leaked information did contain personal data (including that of my seafaring colleague), so they would probably not get away with that argument.

The next step is for the leaking party to notify the victims, and here comes the catch: only if the breach is likely to result in a high risk to them. Once again, the organisation must make that assessment itself, of course based on the GDPR rules. If personal data has been stolen by a hacker, the risk is fairly obvious, according to the AP.

And that is exactly the situation we are dealing with here. Last month, Carnival Corporation, the parent company of Carnival Cruise Line, sent letters to customers about a cybersecurity incident (though not to all customers, obviously). A month earlier, an attacker had gained access to Carnival’s IT systems through social engineering and copied customers’ personal data. The information involved includes names, email addresses, dates of birth, gender, and several Carnival-specific data elements.

Carnival Corporation’s headquarters are located in Miami. Aha, I can hear you thinking gloomily, that is well outside the EU, so that wonderful GDPR is of no use to me. Wrong! The GDPR has what lawyers like to call extraterritorial effect: if a company outside the EU also targets the European market, it falls under the GDPR. And when I add everything up, it seems to me that a personal notification to the affected individuals would indeed be appropriate here.

Unless... Yes, unless the data was encrypted, the breach was stopped before anything could be done with the data, or informing all victims would require a disproportionate effort on the part of the company, for example because it no longer has their contact details. In that last case, publishing a notice in a newspaper or on social media is sufficient.

In short: it is not as straightforward as it may seem. We do know how this particular case played out: it didn't. That is why my data-breached colleague asked me what you can do yourself in such a situation. The AP has put together a useful overview (in Dutch). Among other things, it states that you should change any leaked passwords; that is indeed the very first thing you should do. They also recommend changing the passwords for other accounts and apps if they use the same password as the compromised one.

This immediately shows why you should never reuse passwords: after a breach, it creates a lot of extra work. Criminals will simply take the password from website A and try it on websites B through Z. And of course, you should already have enabled multi-factor authentication wherever possible.

After a breach, you should also be extra alert to phishing attempts. Those phishing messages may be far more sophisticated than the run-of-the-mill phishing emails, because the attackers now have much more than just your email address. With all that additional information, they can make their messages look highly personal.

According to the AP, a criminal cannot do much with just a bank account number (IBAN) or a citizen service number (BSN) on its own. But be careful with combinations of data — a copy of your identity document can be a real game changer when it comes to identity fraud.

In summary: stay alert...

2026-06-12

Leaky cruise

And in the big bad world ...

Leaky cruise