Well, government is like rights. Defined differently in different settings, depending on what kinds of minds are at work.
Market anarchists don't advocate for no government, just no massive central government with absolute authority. Endless local governments and systems of government for different types of associations could be organized by market forces. "Rights" could be protected according to what was called for and what enforcement systems were brought into being by the people concerned.
Governments as we know them are just holdovers from ancient history. Updated rhetoric, maybe, but same basic system. Central authority that can kidnap and kill with impunity. It's not completely logical to say that arrangement is necessary for basic rights to be protected. When you accept that arrangement, you invite large-scale violation of basic rights.