Privacy policy

Last updated: 01.06.2026

We take the protection of your personal data seriously. This policy explains what personal data we process when you use geekBlog, for which purposes and on which legal basis, who receives it, how long it is stored, and which rights you have. The terms used (such as “personal data” or “processing”) have the meaning defined in Art. 4 of the General Data Protection Regulation (GDPR).

1. Controller

The controller responsible for the processing of personal data on this website is:

Christian Prehl
Drachenfelsstr. 5
50939 Köln
Email: webmaster@prehl.de

2. Principles and scope

We process personal data only where necessary to provide a functional, secure website and our content and features. We follow the principle of data minimisation: we do not collect more data than required, and we do not use web analytics, advertising, tracking, social media plugins, or external content delivery networks. All assets (scripts, styles, fonts, images) are served directly from our own server, so simply viewing a page does not disclose your data to third parties beyond the technically necessary access described below.

3. Access data and server log files

When this website is accessed, technically required access data is processed. This may include, in particular, the IP address, time of access, requested URL, referrer, user agent, HTTP status, and technical connection data. This processing is used for secure and stable operation of the website, error analysis, and protection against abuse.

The legal basis is our legitimate interest in operating the website securely and free of disruption (Art. 6(1)(f) GDPR). Access data is stored only for as long as necessary for these purposes and is then deleted; where it is retained for security analysis, it is separated from other data we hold about you.

4. Cookies

We use only strictly necessary, first-party cookies; we do not use advertising, tracking, or analytics cookies, and no third-party cookies are set. Specifically, a session cookie is set after you sign in to keep you logged in, a cookie protects forms against cross-site request forgery (CSRF), and a cookie stores your selected language. These cookies are required for the website to function and are therefore stored on the basis of Section 25(2) of the German Telecommunications Digital Services Data Protection Act (TDDDG); the associated processing is based on Art. 6(1)(f) GDPR. Because we set only essential cookies, no consent banner is required.

Two optional reading aids store settings in your browser's local storage, only when you switch them on yourself: whether the keyboard shortcuts on article pages are turned off, and, if you choose “remember my progress” in a series overview, which articles you have started or finished. This data stays on your device and is never sent to us. You can delete it at any time with “forget my progress” or by clearing your browser's site data. The storage serves a function you explicitly request and is therefore permitted under Section 25(2) no. 2 TDDDG.

5. Sign-in via Google

Signing in is possible exclusively via Google (“Sign in with Google”, OAuth 2.0). When you start the sign-in, you are redirected to Google and authenticate there. After you consent, Google transmits to us the email address and the name associated with your Google account, together with a Google user identifier. We do not receive your Google password.

We use this data to create and manage your user account, to authenticate you, and to enable features that require an account (such as commenting). The legal basis is Art. 6(1)(b) GDPR (provision of the user account you requested); the redirect to and authentication at Google is additionally based on your consent and our legitimate interest in a secure sign-in method (Art. 6(1)(a) and (f) GDPR).

The provider is Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland. In the course of the sign-in, data may also be transferred to Google LLC in the USA. Google LLC is certified under the EU–US Data Privacy Framework, and Google additionally relies on the EU standard contractual clauses for such transfers. Google processes data under its own responsibility for its own purposes as well; details are available in Google’s privacy policy at https://policies.google.com/privacy.

6. User account and public profile

For your account we store your email address, the name provided by Google, and a public username that you choose yourself. Your email address is never displayed publicly. Your public profile shows only your chosen display name together with your published contributions (such as comments). The legal basis is Art. 6(1)(b) GDPR. You can delete your account yourself at any time under “Edit profile”, or request deletion (see “Your rights” below). When you delete your account, your comments are anonymised and their text removed, so replies from other people remain readable.

7. Comments

Signed-in users can post comments. We store the comment text, the time it was created, and the link to your account; the comment is displayed publicly together with your display name and is readable by anyone visiting the page. Please do not include personal data of yourself or others in a comment that you do not want to be publicly visible. The legal basis is Art. 6(1)(b) and (f) GDPR (operating a comment function). Comments remain stored until you or we delete them.

To keep the comment section free of spam and harmful content, the text of a comment is checked by an AI service before it is published. For this the comment text is transmitted to our AI provider OpenAI (OpenAI, L.L.C., USA); the transfer is safeguarded by the EU standard contractual clauses. The legal basis is Art. 6(1)(f) GDPR (our legitimate interest in preventing unlawful and harmful content). A human review of the decision remains possible.

8. Email

Where we send emails — for example account- or system-related messages, or internal notifications to the operators about new comments or technical errors — delivery is handled by an external email service provider that processes the data on our behalf under a data processing agreement. The legal basis is Art. 6(1)(b) and (f) GDPR.

9. Search

If you use the search function, your search term is processed on our server solely to return matching results. It is not stored beyond the technically necessary server logs. The legal basis is Art. 6(1)(f) GDPR.

10. Transport encryption

This website is served exclusively over an encrypted HTTPS/TLS connection to protect the data transmitted between your browser and our server against access by unauthorised parties.

11. Storage period

We store personal data only for as long as necessary for the respective purpose or as required by statutory retention periods. Account data is stored until you delete your account or successfully object to the processing; comments are stored until they are deleted. Access data in server log files is stored only in a shortened, anonymised form (the IP address is truncated) and is rotated regularly.

12. Your rights

Subject to the statutory conditions, you have the right to access your personal data (Art. 15 GDPR), to rectification (Art. 16), to erasure (Art. 17), to restriction of processing (Art. 18), to data portability (Art. 20), and to object to processing (Art. 21). Where processing is based on consent, you may withdraw that consent at any time with effect for the future. To exercise these rights, please contact the controller named above.

You also have the right to lodge a complaint with a data protection supervisory authority, in particular in the Member State of your habitual residence, place of work, or the place of the alleged infringement.

13. Right to object

Where we process personal data on the basis of our legitimate interests (Art. 6(1)(f) GDPR), you have the right to object at any time, on grounds relating to your particular situation, to that processing. We will then no longer process the data concerned unless we can demonstrate compelling legitimate grounds that override your interests, rights, and freedoms, or the processing serves to establish, exercise, or defend legal claims.

14. No automated decision-making

Apart from the automated comment moderation described in section 7, we do not use automated decision-making, including profiling, that produces legal effects concerning you or similarly significantly affects you (Art. 22 GDPR). The comment check does not have such an effect, and a human review of the decision remains possible.

15. Requirement to provide data

Publicly available content can generally be used without signing in. For submissions and moderation features, the required login, session, and content data is necessary. Without this data, the respective features cannot be provided.

16. Changes to this privacy policy

We may amend this privacy policy so that it always reflects the current legal requirements or changes to our features. The version published here at the time of your visit applies.