▁to ▁send ▁subscription ▁requests ; ▁requests ▁were ▁approved ▁for ▁root ▁users , ▁valid ▁U U CP ▁own ers , ▁or ▁system ▁administr ators ▁listed ▁at ▁the ▁N IC . ▁ ▁The ▁open ness ▁of ▁the ▁list ▁to ▁users ▁other ▁than ▁Unix ▁system ▁administr ators ▁was ▁a ▁regular ▁topic ▁of ▁conversation , ▁with ▁participants ▁express ing ▁concern ▁that ▁vulner abilities ▁or ▁explo itation ▁details ▁dis closed ▁on ▁the ▁list ▁were ▁li able ▁to ▁spread ▁to ▁hack ers . ▁On ▁the ▁other ▁hand , ▁the ▁circul ation ▁of ▁Z ard oz ▁post ings ▁among ▁computer ▁hack ers ▁was ▁an ▁open ▁secret , ▁mock ed ▁open ly ▁in ▁a ▁famous ▁Ph rack ▁par ody ▁of ▁an ▁I RC ▁channel ▁populated ▁by ▁notable ▁security ▁exper ts . ▁ ▁Notable ▁participants ▁▁ ▁Keith ▁B ost ic ▁discussed ▁B SD ▁Send mail ▁vulner abilities ▁ ▁Ch ip ▁Sal zen berg ▁discussed ▁Peter ▁H one yman ' s ▁posting ▁of ▁a ▁U U CP ▁w orm , ▁and ▁shell ▁script ▁security ▁ ▁Gene ▁Sp aff ord ▁discussed ▁V MS ▁and ▁Ult rix ▁bugs , ▁and ▁relay ed ▁law ▁enfor cement ▁en qui ries ▁about ▁the ▁Morris ▁W orm ▁ ▁Tom ▁Christians en ▁discussed ▁S UID ▁shell ▁scripts ▁ ▁Chris ▁T ore k ▁discussed ▁de vis ing ▁explo its ▁from ▁general ▁descri ptions ▁of ▁vulner abilities ▁ ▁Henry ▁Sp encer ▁discussed ▁Unix ▁security ▁ ▁Br end an ▁Ke ho e ▁discussed ▁systems ▁security ▁ ▁Ale c ▁M uff ett ▁announced ▁Cra ck , ▁the ▁famous ▁Unix ▁password ▁cra cker ▁ ▁The