I believe one poster was using several screen names simultaneously to play multiple parts in the "drama".
S/he was posing as a guy from LA who made a lot of comments that sounded as if he was saying he had thrown away Sierra's inhaler because of an argument, that the police knew/were "in on" the abduction, and had been complicit in her being sold into white slavery in Mexico, but that she has been hurt in some way to a degree that, even if found, she's of no value to anyone.
He was also overtly threatening Sierra's friends. One such friend claimed she had found a "sweater" just that very day, and that DNA tests had been completed and showed it bore Sierra's blood. Later on, this girl stated that she was being bullied by the "guy" and according to her supposed cousin, she shot herself over the stress.
If the girl lived within a thousand miles of where Sierra had vanished, I would believe she knew Sierra and participated in the search, but the "sweater" she claimed to have found seemed to be a reference to this Nike shirt found weeks before, and even if it had been another garment found that day, DNA testing takes weeks.
I think one person played all the parts, logged in from different devices, and the entire purpose was to upset Sierra's friends and searchers.