[Aengeuad]

The line is drawn at surveillance of a public place [0] and in this instance only in Austria, as other commentors have pointed out the laws may have changed in 2018 to allow for dashcams that continuously overwrite old footage but I can't verify that. It is not illegal to make recordings in a public place in Austria, although you may have some limitations on what you can do with that footage if it captured other people and those limitations may change depending on what was captured (i.e., whether it was incidental, or footage of a crowd).

In Germany for instance dashcams are perfectly legal, you only have conditions on what you can do with that footage afterwards, for instance posting it on Youtube or social media is a big no-no, and unlike Austria you're likely to get a warning in Germany instead of a fine [1].

[0] https://helpv2.orf.at/stories/1717004/index.html

[1] https://www.derstandard.de/story/2000092017999/erst-vier-str...