Law Enforcement
Different approaches by the British and Taiwanese police

“We do not deal with individual spam related scams but target the criminal network behind them. We aim to stop the problem at its source,” said the Metropolitan Police Service Computer Crime Unit (CCU) press officer Helen Kennedy.

However, Taiwanese police do tackle individual spam cases which involve other criminal activities such as scam and phishing.

“We would track their webpages and cash flow. But the problem is a lot of their bank accounts are bogus. And people who sell their accounts to criminals don’t know who they have sold to because the deal was done online,” said Central Police University assistant professor Robert Weiping Chang, who specialises in computer forensics and computer crime investigation.

He was head of Information Management Office (IMO), National Police Agency in Taiwan from 1997 to 2004.

“We find in some cases vagrants were coaxed to open an account and they didn’t even know who took them to the bank.

“Through legal procedures we are able to monitor from ISPs’ servers. But the best way is to seize all the evidence at the crime scene.”

Computer forensics cracking cases

“We’ve once restored data from a burned computer in a fire. We’ve also recovered data from a formatted computer,” professor Chang said.

He gave me an example of how to reveal volatile digital evidence that is deleted by criminals.

“When you delete a file, the computer is simply marking it saying it’s deleted but not actually deleting it. What it does is only sparing some space for other data.

“Let’s say a file the size of 1,000 KB is ‘deleted’. It’s actually marked as ‘deleted’ but not wiped. Now, if a 400 KB file needs to be saved, it will look for space available and possibly overwrites 400 KB out of the 1,000 KB space the previous file used to occupy.

“As long as the ‘deleted’ file is not completely overwritten by other data, we can definitely recover 600 KB out of the 1,000 KB file. This unwiped data may contain key clues.”

Prompt international cooperation is paramount

During his term as head of IMO, professor Chang was also a liaison officer corresponding with international police forces. He established a practical and instant mechanism to combat cyber crimes.

“Electronic data may have already been destroyed after all the red tape between countries. It’s particularly hard for Taiwan if we don’t have diplomatic ties with the country. So intelligence exchange on an unofficial level is very important and mutually beneficial.”

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