Shift+Ins was the default paste on Windows 3.0, before Apple sued Microsoft for copying their OS (back in then it was still called just "System"), so MS added Ctrl+C for Windows 3.1, but the old one still work.
Same thing for Xorg. Ctrl+Ins for copy, Ctrl+Del for paste and Ctrl+Ins for paste.
This has been the law in Brazil for more than 10 years now. We have lots of problems here, but at least our consumer protection laws are top notch. And, believe or not, they're enforced successfully.