1. Are you willing to invest the money to go after them? Good lawyers are expensive (think hundreds of euros per hour) 2. Courts generally move slow. It might

1. Are you willing to invest the money to go after them? Good lawyers are expensive (think hundreds of euros per hour) 2. Courts generally move slow. It might take years before you have a positive judgement. You will likely need to sue in their jurisdiction, which puts you at a disadvantage because you do not know the language and legal procedures. 3. And this is the most important one: even if you get a positive judgement, the company is likely to be a limited liability company which can declare bankruptcy. Did they set up an SPV (read: https://en.wikipedia.org/wiki/Special-purpose_entity https://en.wikipedia.org/wiki/Special-purpose_entity) for this project, or is this a larger company with stable revenue and profits that has done this? If at the end of the day you can collect €150,000 (as an example), you might go and collect from someone with no cash in their account. They can and will declare bankruptcy. Then you're out of pocket legal fees, with no way of recovering them, and with no compensation. Consider this before you decide to sue. It might be easier to just sell them the tech for a reasonable amount of money. I would not threaten to "expose" them with the H2020 programme as this might take away their source of funding -- it makes it less likely they will buy your tech. I would reach out with a friendly email, telling them you noticed they used your library, and that you are aware they received funding because of it. Offer to sell them the library for a reasonable amount.