I've only blacklisted emote spammers but then removed them once I finished checking my retainers or doing GC turn-ins whatever the case might be. Think I might have one or two still on some alts' blacklists that I forgot to remove. Is it healthy to have an overly full blacklist? Probably not, at least for me I don't like keeping the names of asshats on a list to remind me they exist. And if the rare instance of continued harassment occurs, I report and ignore.