TULSA, Oklahoma - As we go about our daily lives the FBI is working behind the scenes, trying to keep us safe from bad guys and threats to our way of life.

But what else is the Bureau up to?

It turns out the FBI has also been keeping tabs on some famous Oklahomans, and when they died their files were open to the public.

We gave the FBI a long list of names they sent back copies of bureau documents and memos, discs full of once-classified information and newspaper articles.

From Pretty Boy Floyd to Mickey Mantle, many of the files offer a glimpse into the real life struggles of famous Oklahomans. Others give context to the legacies they left behind.

Charles Arthur Floyd moved to Oklahoma as a boy and grew up to be the infamous Pretty Boy Floyd, highway robber, bank robber and killer.

Inside his file there’s an internal FBI memo dated April 18, 1933, sent to then DirectorJ.J Edgar Hoover. It's Floyd's criminal record, beginning with a 1925 highway robbery and ending with four arrests in Kansas City for holdups, noting that Floyd was released each time.

"They were lining Charlie up to be public enemy number one, which he became,” said Tulsa Author, Michael Wallis.

Just two months after Hoover received that document, Pretty Boy Floyd and some other outlaws were accused of the mass murders known as the Kansas City Massacres.

Wallis wrote a book on Pretty Boy Floyd. He claims Floyd never took part in the massacres and the document was all part of Hoover's campaign to make Floyd another celebrity outlaw who would generate big headlines.

"He was a criminal, no doubt about it, but I guarantee you he was blamed for much more than he actually did, bank robberies and killings,” Wallis said.

FBI agents and Ohio police killed Floyd the following year in a gun battle.

Tulsa televangelist Oral Roberts has a relatively a thick FBI file. It's full of complaints from people asking the FBI to investigate Roberts televised faith healings, many calling him a fraud, others a swindler.

In a letter from the Chief of Police on the island of Samoa, Roberts' healing ceremonies are described as, "a lot of Tommy rot," and he worries Roberts will gain, "a large following," and be financially rewarded.

The FBI under J. Edgar Hoover never investigated Roberts according to documents written by Hoover himself.

There is something interesting, however, a letter from J. Edgar Hoover requesting a copy of Roberts' autobiography. It's unclear whether that came before or after a letter, which appears to be from Roberts, upset, thinking he was being tracked by the FBI.

Roberts included pictures of himself, to be put in his FBI File, saying, "If you folks ever want to trace or locate me in the future," there's always TV.

There were also death threats against Roberts; two of them in the FBI file. One from a man tired of receiving Oral Roberts' prayer forms, another from an institutionalized person who threatened to kill Roberts and Richard Nixon.

But Roberts wasn't the only famous Oklahoman to receive disturbing mail.

Sam Walton, a Kingfisher native and the founder of Walmart, sent a letter to the FBI. In it, someone threatened to bury kids in a hole full of water if Walton didn't make three $500 million payments to a Swiss bank account.

In Oil tycoon, Frank Phillips' FBI file there’s a letter demanding Phillips put $3,000 in a sack and throw it off a Collinsville bridge. Otherwise, the writer said his life would be short.

Even the sooner state's most famous slugger, Mickey Mantle, had enemies.

The FBI investigated two threatening letters sent to Mantle. One from 1960 reads, "I have a gun with microscopic lenses and I'm going to get you through both of your knees."

The other, later considered a prank from a young baseball fan, said, "your career will come to an end with a .32, signed a loyal Red Sox fan.”

We showed Mantle's file to his sister, Barbara Delise. She did not know about the FBI investigations, but isn't surprised.

"Probably just jealous, maybe of him and what he did," Delise said. "Maybe they thought he had a lot of money, which he didn't."

That may explain why he was blackmailed as a 1956 file states, for $15,000 after "being found in a compromising situation with a married woman."

Mantle admitted he had, "shacked up," with many girls in New York City, but denied ever getting caught.

Who else does the FBI keep files on? Are they watching us?

Agents say probably not. They don't have the manpower or desire to keep files on everyone, and laws passed in recent decades make it illegal.