This element of the case began in August 2018, when an FBI special agent told the court in an affidavit that "there is no practical method available by which law enforcement can monitor these calls" between suspected MS-13 gangsters. Authorities already had traditional wiretaps and were able to intercept written messages between the defendants, who are now in custody. (emphasis mine)

Sounds like the multiple times that terrorists have been caught communicating using simple SMS (or it was revealed after the attack that they were only using SMS). How often does the opposite occur?

Are there any organizations I can support other than the ACLU that has fought for internet freedom and against government mass surveillance?

EPIC [1]

[1] https://www.epic.org/

EFF

ACLU is unaware that FB has an entire Haskell library for snooping on messages in the name of SPAM detection? https://code.fb.com/security/fighting-spam-with-haskell/