There is electronic filing of documents throughout the federal court system now, noted veteran criminal defense attorney and Fourth Amendment expert John Wesley Hall of Little Rock, Ark.

"I think it's a natural progression," he said. "When [the rule] says 'by other electronic means,' what else can it mean but e-mail? We heard years and years ago about businessmen having portable computers and printers in their cars. I'm sure you could get a cheap laptop and printer and have it right there at scene of the search."

....Warrants via e-mail are probably "better all around" than warrants secured over the telephone, Hall added, which are quite common today. The latter, he explained, rely on the memory of the police officer. "There may be more protection for citizens with an electronic filing," Hall said.

But the defense attorney added, "I just worry. We have to wait and see how the first few cases go, whether or not cops do it badly. It's too easy to dash off e-mail without thinking. I would think the risk on the cop side would be that the affidavit for the search warrant is just dashed off in e-mail instead of thought out and composed on the computer." And that, he added, could lead to more attacks on probable cause for the e-mail warrant.

"General human experience with e-mails being what it is, affidavits are going to get more cursory than they already are."

....It may work to the benefit of the defense," Hall said. "Of course, knowing the courts, I doubt it. What will be really interesting would be the text-message warrant-that's the next stage. Read it on the screen of a cellphone or BlackBerry; show it to the target of the search.

"I'm kind of looking forward to it. Something new to litigate and I'm always looking for something new to litigate."