AT&T recently announced a $250,000 reward to anyone with information on whoever entered its underground facilities in Livermore, California – a San Francisco suburb – and severed two of its fiber cables earlier this week, USA Today reported yesterday.

The vandalism echoes 14 similar attacks that have destroyed damaged fiber cables and disrupted internet service for customers of several service providers in the northern California region dating back to July 2014.

USA Today also reported a similar attack in late June, when "someone broke into an underground vault and cut three fiber-optic cables belonging to Colorado-based service providers Level 3 and Zayo," according to an earlier USA Today report. The FBI confirmed at the time that it was investigating connections between that attack and 11 similar outages in the region over the year prior.

Authorities have speculated that the perpetrator could be anyone from a disgruntled former employee to a terrorist organization testing infrastructure and disaster response efforts, and have said that they may disguise themselves as utility company employees while carrying out the attacks, according to USA Today.

At least one cybersecurity expert has given credibility to the terrorism speculation.

"When it's situations that are scattered all in one geography, that raises the possibility that they are testing out capabilities, response times and impact," JJ Thompson, CEO of cybersecurity consulting and services firm Rook Security, told USA Today earlier this summer. "That is a security person's nightmare."

Regardless, both the authorities and the internet service providers appear desperate to find any information about those responsible.

"When it affects multiple companies and cities, it does become disturbing," FBI Special Agent Greg Wuthrich told USA Today in June. "We definitely need the public's assistance."