Open Source often means more than just "free and accessible source code"; it also encompasses license models for free, unrestricted use. Yet, there are companies that successfully develop high-quality, commercially viable software with significant financial investment and a dedicated team of developers. Revenue is generated through "service and support" contracts, quality-tested releases, troubleshooting with short SLAs, or assistance with rollout and operation. This is based on the general understanding and acceptance that manufacturers need to be financially compensated for the use of their software, even if it is available as FOSS. As Open Source becomes more popular in public administration, procurement projects are increasingly being tendered solely on price. This attracts bidders who neither internalize nor share the principles of free software: Parasitic freeloaders offering third-party software on pure operational terms without any manufacturer compensation, consistently outbidding the manufacturer or its partners. Like a cuckoo, they shirk the work of raising their young onto others, even killing their offspring and peers in the process. The consequences are devastating. If this happens systematically and regularly, it rapidly deprives any further development of Open Source software of its financial foundation. The Open Source ecosystem is ruthlessly destroyed by freeloaders who play against the rules. How can Open Source projects protect themselves against this abuse? Various associations and providers are currently launching initiatives to ensure fair and sustainable procurement of Open Source software. A "Code of Conduct" could foster a common understanding. Ultimately, the tendering entities and public procurement officers need to be convinced that pure tenders seeking only the cheapest bidder destroy their future choices. And there are legal tasks to be accomplished: What might legally robust "Fair Use" clauses look like that could become mandatory criteria for tenders?