AUSTIN, Texas (CBSDFW/AP) – Authorities are investigating interference with radio communications and websites or networks used by police and other officials during protests over the death of George Floyd in Minneapolis.

Thousand spilled into the streets of North Texas in the days following Floyd’s death. Their message was clear, shining light back onto Dallas and Fort Worth’s own history of police brutality.

The sister of Botham Jean, an unarmed black man who was killed by white, off-duty officer Amber Guyger as he sat eating ice cream in his southside Dallas apartment attended Floyd’s funeral. Botham’s name, along with that of another black woman killed in her own Fort Worth home — Atatiana Jefferson were also seen on signs during the recent protests targeted by hackers.

Although the disruptions in Minnesota, Illinois and Texas aren’t considered technically difficult hacks, federal intelligence officials warn that law enforcement should prepare for such tactics to persist.

Authorities are particularly concerned about interruptions to police radio frequencies as dispatchers tried to direct responses to large protests during the last weekend of May.

No one responsible was identified yet and few details about how the disruptions were carried out are known.

DALLAS, TX – JUNE 06: Demonstrators march past a Dallas Police car during a peaceful protest against police brutality and racism on June 6, 2020 in Dallas, Texas. This is the 12th day of protests since George Floyd died in Minneapolis police custody on May 25. (Photo by Cooper Neill/Getty Images)