Digital safeguards badly hit non-digital phones? (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

for definition, ‘digits’ as in fingers anagram/”badly” of (hit)*, plus M- O -BILES=”phones” non-digital i.e. minus O =0=’the digit zero’ edit thanks to Niltac in the comments: also minus the I=1=’the digit one’