WHITTEMORE, Mich. (AP) — A northern Michigan man said he placed pipe bombs outside two phone stores because he was upset with “immoral content” on phones and cable TV, according to the FBI.

Authorities filed charges Tuesday against John D. Allen of Whittemore, less than a week after explosives and notes threatening Verizon and AT&T were found at phone stores in Sault Ste. Marie and Cheboygan.

READ MORE: MRLA Offering Free Food Safety Classes for Kids

The boxes also contained handcuffs. “HJ” and “Handcuff Johnny” were written on the boxes, apparently references to Allen, the FBI said. No one was hurt.

Allen, 75, was confronted by agents Monday and said he acted alone.

“Allen stated that he created and placed the letters and bombs because he became dissatisfied with all of the immoral content, including pornography, on phones and cable television,” the FBI said in a court filing.

Allen also is accused of writing letters found last month at communication towers across Michigan’s Upper Peninsula. The letters made threats and claimed to be from the “Coalition for Moral Telecommunications.”

READ MORE: Whitmer: $32M Investment To Recruit, Retain Police Officers

Allen appeared in court on charges of extortion and attempted destruction of buildings. A message-seeking comment was left for his attorney.

Photos from the Mackinac Bridge and video from the phone stores greatly helped agents.

Allen used a California license plate at one point but said “he realized that he had made a mistake when he noticed the emblem for the auto dealership on the rear of the vehicle could not be removed,” according to the FBI.

Indeed, agents got information about Allen, the owner of the 2006 Chevrolet Uplander, after visiting a dealer in Standish.

MORE NEWS: Deputies Find Human Remains In Mid-Michigan Soybean Field

© 2021 Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.