Here's some advice for anyone hoping not to get caught in an insider trading web: Shut up.

After the October 2009 arrest of Galleon Group hedge fund founder Raj Rajaratnam, who was wiretapped by the FBI, the world woke to a new era of prosecutorial tactics in insider trading probes.

For those considering crossing the line, the changes may make insider trading seem a vocation not worth the risk.

Emails and other forms of electronic communication can be traced. Destroying old-fashioned snail mail or hard drives will not work if the government gets a tip it is being done.

And don't talk to people. There is no certainty that what is said will remain private. Indeed, recent phone recordings make some accused wrongdoers come across as Keystone Kriminals.

Insider trading today is a lot more difficult to get away with than it was 20 years ago, said Andrew Stoltmann, a principal at Stoltmann Law Offices PC in Chicago who has handled civil insider trading cases. Prosecutors really are cracking down. And there are electronic trails left behind.

GARBAGE CANS AND GARBAGE TRUCKS

A recent proliferation of cases against fund managers, traders and lawyers shows a new aggression, especially in the use of wiretaps and recorded phone calls to build cases.

The latest illustration: this week's arrests of lawyer Matthew Kluger and trader Garrett Bauer.

Prosecutors say the men ran a 17-year conspiracy tied to tips on mergers that Kluger stole while working at high-octane law firms. They have yet to enter pleas in the case.

Twelve single-spaced pages of a criminal complaint detail nervous calls that Kluger or Bauer had with an unnamed co-conspirator, once they thought the government was on their tails.

I got rid of my computer, Kluger was recorded as saying on March 17. I got rid of my iPhone where I had looked up some stock quotes. Those are gone. I mean history. Gone.

Bauer was recorded a day later as needing more effort to dump his prepaid cellphone.

I broke the phone in half and went to McDonald's and put it in two different garbage cans, he said, according to the complaint. Someone was watching me. I thought it was an FBI agent. And I asked him, 'Do you know me? You look familiar.'

Prosecutors say hedge fund manager Donald Longueuil, a defendant in another insider trading case, used a similar modus operandi.

They contend he once took to the streets of Manhattan at 2 a.m. to find places to toss a flash drive and two hard drives that had incriminating evidence.

I go on like a 20-block walk, he said in a recorded conversation. And threw the shit in the back of like random garbage trucks, different garbage trucks ... four different garbage trucks.

Then there were Bonnie and Yonni -- former Walt Disney Co assistant Bonnie Hoxie and her boyfriend Yonni Sebbag.

Last year, Sebbag tried to sell Disney secrets that Hoxie learned at her job to some 30 hedge funds and other investors. Prosecutors said he used a FedEx Kinko's computer for the deed.

Bad idea. Google found the computer, and several funds went to the authorities. Both defendants admitted their guilt. Sebbag was sentenced to 27 months in prison. Hoxie got probation.

CANADA TOO

Two years ago, Canadian prosecutors said lawyer Gil Cornblum and his friend Stanko Grmovsek relied on pay phones for several years as part of a 14-year insider trading conspiracy based on secrets Cornblum learned at his job.

Cornblum committed suicide by jumping from a Toronto bridge in October 2009, a day before Grmovsek pleaded guilty.

Prosecutors say Rajaratnam, a one-time billionaire, also tried to cover his tracks.

Rajaratnam has pleaded not guilty. He is set to begin his defense next week in Manhattan federal court, in Wall Street's bigger insider trading case since the prosecutions of Ivan Boesky and Michael Milken more than two decades ago.

Anil Kumar, a former McKinsey & Co consultant arrested with Rajaratnam and now cooperating with the government, last month testified to having lolled with his longtime friend in a pair of deck chairs in Miami Beach, just prior to their arrests.

You know, Anil, I'm told there's a gentleman who used to work for me and he's now wearing a wire, Kumar recalled Rajaratnam as saying.

You should be careful, Kumar said he responded. You should make prepaid phone calls to me.

(Reporting by Jonathan Stempel in New York; editing by John Wallace)