The FBI has arrested a man in San Antonio and accused him of using the micro-blogging service Twitter to threaten a high-level executive of Google Inc..

Gregory Calvin King, 27, appeared in federal court here on Monday. He was arrested late Friday on charges he sent the woman hundreds of demeaning, disparaging or threatening tweets. According to court documents, some of the messages — cryptic, vulgar, sexually explicit, laced with profanity — included rants against Jews and against Google. Some mentioned shooting her.

The FBI would not comment on the victim and a criminal complaint affidavit didn't name her but stated she is one of the first 20 employees hired by Google and is now an executive there. A review of one of King's three Twitter accounts show the tweets were directed at Marissa Mayer, the company's first female engineer and now vice president of search products and user experience.

A profile of Mayer in the New York Times called her Google employee No. 20, the “it girl” of one of the world's most important companies. Other publications estimated her net worth at $300 million. In 2008, at age 33, she became the youngest on Fortune magazine's Most Powerful Women list, at No. 50.

Several messages seeking comment from Mayer and from Google were not returned Monday.

King was charged with making threats through interstate communications and with making harassing interstate communications. He could face a maximum sentence of five years in prison and a $250,000 fine on the first charge and two years and a $250,000 fine on the second.

The FBI began investigating King after Google's corporate security in February reported that an executive was being harassed via Twitter, the affidavit said. Almost every day from Nov. 1 through early August, tweets originating from accounts linked to King were sent to the victim, some originating in Virginia or Texas, FBI agents found.

The FBI interviewed the victim in April, who told agents that she was worried.

“Due to some of the explicit sexual and violent tweets, the victim expressed concern for his/her safety and the safety of his/her spouse,” the affidavit said. “Specific details contained in some of the tweets led the victim to speculate that King had previously done extensive research of the victim including information that was not public, and continued to monitor her activities via the Internet on a daily basis.”

Julie Stone, a spokeswoman for the FBI in San Francisco, said there is no known connection between King and the victim. She and special agent Erik Vasys, spokesman for the FBI in San Antonio, said agents in the Alamo City arrested King after he apparently relocated here from Virginia.

U.S. Magistrate Judge Nancy Nowak ordered King held without bond pending a bail hearing on Thursday.