I noticed some strange traffic in my logs and identified that it was a company called Censys who were port scanning me on a daily basis. Apparently they scan 3,552 ports across the whole public IP space, which includes home users on domestic ISPs. They are attempting to identify and log any services you might be running. This includes web, databases, IoT, remote access, file-sharing, crypto, and gaming.
The legality of port scanning is a tricky area, especially when crossing international borders. However, the behaviour of Censys is certainly contrary to good etiquette guidance. Remember that in GDPR terms your IP address is personal data.
To "opt out" of this intrusive behaviour you need to configure your router/firewall to drop traffic from the following subnets: