Can reselling be illegal?

Can reselling be considered illegal, and if so, under what circumstances? It's a question that often arises in the world of cryptocurrency and finance, especially when dealing with digital assets and collectibles. Is there a legal framework in place that governs the resale of these items, or is it largely unregulated? And if reselling is deemed illegal, what are the potential consequences for those who engage in it? Understanding the legal implications of reselling is crucial for anyone looking to navigate the complex landscape of cryptocurrency and finance.