It depends on the country, in Canada you can certainly report them to the CRTC as breaking the law (CASL). http://www.crtc.gc.ca/eng/casl-lcap.htm

Emailing someone in Canada now requires consent (various legal ways) or close personal relationship. It doesn't cost anything to report them https://services.crtc.gc.ca/pub/rapidsccm/Default-Defaut.asp... . But if you really wanted to pursue them, you would have to hire a lawyer, a complaint doesn't have the same weight or speed of a legal filing.

This just goes to show you has clueless the developers are with regards to international policy and law.