The Close method closes the response stream and releases the connection to the FTP server for reuse by other requests

CAUTION: You must call either the Close()()()() or the FtpWebResponse.Close method to close the stream and release the connection for reuse. It is not necessary to call both Stream.Close and FtpWebResponse.Close, but doing so does not cause an error. Failure to close the stream will cause it to remain open and your application may run out of connections.

.NET Compact Framework