I agree it could be easier to add folks to ignore, however /blist add <Name> also works. I use a macro to blacklist the last person to send me a tell for the ones that do that. For the shouters, I right click the name in the chatlog, select "send tell" and then left-arrow to /tell, delete it, and replace it with /blist add

Always report the spammers you blacklist, as it will help to get them off the server. If we can keep them from making their 30 bucks back before the account is banned, it helps to keep their numbers down.

I have recently noticed more gil spammers with non-random character names. I presume that these folks have either used a leveling service, or are hacked accounts. Either way, account security is your friend