Tip of the Week: Identifiers

Avoid accidental identifiers

With etracker Analytics, the IP address is automatically anonymized in the working memory of the data acceptance servers – that is, at the earliest possible time. Additionally, there is now an automatism for anonymizing identifiers in page URLs according to the privacy-by-design principle.

Please note: Since such IDs can have very different characteristics, the automatism with heuristic procedures cannot replace individual verification in reporting.

Example of a URL with ID:


Result in reporting with automatic anonymization:


In URL parameters, IDs are only captured if the corresponding parameters are explicitly included in the capture. In this case, automatic anonymization applies analogously.

Why are identifiers critical?

If session or user IDs are captured, data protection aspects must be taken into account on the one hand, and on the other hand, the analyzability of the data and the loading time of the reports are affected due to the unnecessarily increased cardinality.

In addition to the negative impact on the analyses, identifiers may also have a personal reference. In this case, there may be a violation of Art. 5 GDPR, which requires data minimization as one of the principles of the processing of personal data: Therefore, personal data must be “limited to what is necessary for the purposes of the processing”.

According to the ruling of the Court of Justice of the European Union (EuG) of 26.4.2023 (Az: T-557/20), the following conditions must exist for a possible personal reference in the case of IDs:

  1. In contrast to anonymous data, the person behind the ID can be re-identified by drawing on additional, separately stored information.
  2. The data recipient(s) have this re-identification information or have legal means to access such information.

This means that when using Google Analytics, website operators must also consider, among other things, what possibilities Google itself has for re-identification, since Google is not only a processor, but also a data recipient.

What to do if identifiers are explicitly wanted?

Two cases must be distinguished here:

  1. The actual ID is irrelevant in the evaluation. It is only a question of whether an ID is present, for example to distinguish between visits with and without a login.

    Since the anonymization replaces the parameter value, but not the parameter as such, you can simply filter by the corresponding parameter, for example:

  2. The respective ID is relevant as for remarketing purposes or other matching. In this case, a custom segment dimension can be used either at visit or user level. To do this, go to Settings → Account → Data enrichment → Own dimensions.

The new automatism thus strengthens the data protection friendliness of etracker Analytics and at the same time makes it easier and faster to analyze.

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