Not completely. For example, if the analyst has a large corpus from someone's main account to build up a profile, it seems plausible to me that they could ident

Not completely. For example, if the analyst has a large corpus from someone's main account to build up a profile, it seems plausible to me that they could identify individual comments under the "deleted" user as being written by the same person using a throwaway account, especially if they have a distinctive writing style.