It was passed at the end of June, ahead of last month's federal election, but only came into force on Sunday.
Local media is fond of calling the NetzDG the 'Facebook law', and most discussions around the legislation have indeed focused on the biggest names in social networking: Facebook, Twitter, and Google's YouTube.
However, according to unnamed sources cited in a report in Der Spiegel, the German justice ministry also intends to launch inspections of slightly less obvious services: Reddit, Tumblr, Vimeo, and even Yahoo's Flickr photo-sharing service.
The first tranche of services to fall under the justice ministry's microscope reportedly also includes VK, Russia's most popular social network, and Gab, a US-based alternative to Twitter that was set up for the alt-right crowd last year in protest at Twitter's crackdown on abuse.
Josephine Steffen, a spokeswoman for the justice ministry, declined to specify which platforms would be covered under the law, saying the department would first need to commence its investigations.
To fall under the NetzDG, a social-networking service must have at least two million registered users in Germany, arguably not a useful way of analyzing the issue because many people register for a service and never use it, and many may not give accurate information about their country at registration.
However, not many companies provide this breakdown themselves, with estimates generally coming from third-party services. The justice ministry still needs to figure out what the real figures are.
The ministry is assembling a team of 50 people to work on enforcing the new law. Steffen said half are already operational, and the other half will be on board by the start of next year, when a transitional period ends.
The law requires the relevant services not only to take down objectionable material within somewhere between a day and a week, depending on the complexity of the case, but also to have someone on the ground in Germany to act as a contact point for complainants and investigators.
It remains to be seen whether the likes of VK and Gab, both of which are popular with the far right, would agree to set up this sort of infrastructure within Germany, or indeed how it would be able to enforce the law on them if they don't comply.
The NetzDG law has been highly controversial, with figures such as United Nations free speech rapporteur David Kaye warning that social networks have too many incentives to over-block content rather than challenging takedown requests. The constitutionality of the law may also still be tested in court.
However, Steffen of the justice ministry insisted that the aim of the NetzDG was to "ensure a free, open and democratic culture of communication and to protect those affected by hate crimes by groups and individuals".