Federal Judge Loretta Preska says Jeremy Hammond poses "a very substantial danger to the community." She rejected arguments by his lawyers Tuesday that he be freed on bail secured by houses owned by relatives.
Prosecutors call Hammond a flight risk and a danger to the community.
Hammond has been held since his March arrest. The judge says he has demonstrated a lack of respect for court orders and a sophisticated ability to get into databases online and obtain information including credit card numbers.
Hammond has pleaded not guilty in website attacks the government says were carried out by the loosely organized worldwide hacking group Anonymous.