There have been two cases in which this has come up int the US and both had differing opinions.

California: Cops do not need a warrant to search: http://legalmatch.typepad.com/criminallaw/2011/01/california-supreme-court-police-can-search-cell-phone-without-a-warrant.html

"If you’ve got a cellphone on you, the police can search it during a lawful arrest (including going through saved text messages, phone numbers, etc.), and they don’t need a warrant. So says the California Supreme Court - here’s the full opinion (PDF)."

Ohio: Cops do need a warrant to search a cell phone: http://www.huffingtonpost.com/2009/12/15/cell-phone-searches-requi_n_393063.html

"The Ohio Supreme Court said Tuesday police officers must obtain a search warrant before scouring the contents of a suspect's cell phone, unless their safety is in danger.

The American Civil Liberties Union of Ohio described the ruling as a landmark case. The issue appears never to have reached another state high court or the U.S. Supreme Court."

What are your thoughts on this? Should it be ok to search? Under what cirumstances? Should this apply to cell phone/smart phone/tablet pc/laptop equally?

Smartphones are becoming personal computers and you should need a warrant to search a computer.

I think if your carrying it on your person and it pertains to the case then a warrant should not be nescessary. Its essentially like searching someones pockets for buisness cards or a liscense, you don't require a warrant to search a man. In cases like drug dealings and pimps the data on that phone could save lives and liberate women and lead to the arrests of criminals.

Galaki points out Cell phones are becoming computers. The difference is you need a warrant to search someones house and their for computer. But if the guy is carrying the phone on him outside of his personal residence then it should be fully legal for a police officer to search the phone.

Under extrodenary circumstances it would be vital. Example someone was kidnapped and police nab a suspect. In their pat down they find a phone with the numbers of the other kidnappers on it, they can now trace the numbers and locate the kidnappers. Or what about a teenager picked up for posession or involved in an assualt, the kid gives a false name and tries to hide their identity, the police can check the phone call the parents and get the kid help.

I think if your carrying it on your person then legally a police officer has the right to search it just like a notebook, phone book, wallet. You don't need warrants to search those so why should you need a warrant to search a virtual version of those?

Yes. They definately should need to have a warrant to search a cellphone. I mean, if they'd want to search my phonme I'd need time to erase all those naughty pictures I have on it.

A phone is not just a notebook, phonebook or wallet. It carries a huge amount more information.

In the situations you mentioned (the first one for sure) a warrant would be granted, so why is it vital?

Do they need a warrant to get your call records from your carrier?

Warrants take time to grant sometimes days. In a case of a pimp being busted or a kidnapping the kidnappers or homies or what ever you call a pimps cronies would have time to move the women or kidnapped child to a different location.

I thought of another scenerio. What if someone is going to carry out a bombing or is suspected of terrorist activity. They get arrested, the phone could be the trigger device and it could carry information about the target of the attack and the accomplaces.

Again a warrant would be issued but not in time to prevent a terrorist attack.

You could make these exact same arguments however about a computer say, or even somebodies house. Warrants exist for a reason and the reason applies to phones in my opinion. They are essentially to stop abuse of power and invasion of privacy.

In any case, do you have any stats on how long it takes for a warrant to be served in cases where there is time pressure (such as kidnapping)?

Nope no stats. I would love info on the stats but I know from reading and watching the news that warrants don't get written in a day or so. Its a process that takes time. But I would be interested in finding out just how fast a warrant can be written up. If anyone works in law enforcement it would be nice to know.

Yes, cops should have to have a search warrant to search a cell phone.