US magistrate Judge James P. Donohue turned down Soloway's appeal for bail because he has few ties to the country as most of his family live in Sweden.
He also said that, because spamming could be organised from any country Soloway would have to stay in prison until his hearing on 6 August.
"These are allegations of cyber-crimes that have no geographical borders," Judge Donohue said, according to Associated Press. "It is just as easy to continue these actions in Sweden as it is in the US."
Another factor against Soloway was his refusal to abide by earlier court judgements. Microsoft and others have won cases against him and been awarded US$17m in damages, which has yet to be paid.
Soloway was arrested on 30 May on 35 charges including mail fraud, wire fraud, aggravated identity theft and money laundering. Mail fraud, wire fraud and money laundering are punishable by up to 20 years in prison.
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iTnews Executive Retreat - Security Leaders Edition
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