Using a KV.bin generator (even a fake one) or a stolen KV is a violation of the Xbox Live Terms of Service. While Microsoft no longer issues hardware bans (you are banned at the console ID level, not your Microsoft account), repeatedly using blacklisted KVs can lead to:

The Xbox logo swirled. The dashboard loaded. He clicked "Sign In."

Since one console = one KV, there is a limited supply. Sellers on specialized forums or sites like Console Warehouse sell these "unbanned" KVs for around $5 to $10. 4. The Unbanning Process