People are using the Fireteam Search page, but having their fireteam set to clan and friends only. And of course you can't message them to let them know without adding them on Steam (afaik). I suggest Bungie put a notice on the create Fireteam Search page to remind players to check their privacy settings before creating a group, either just a general notice, clearly visible on the page, or one that checks the privacy and doesn't let you create the search until you've changed it. Alternatively, the game could send a message to the player when you try to join, saying "xxx tried to join your Fireteam but was unable due to your privacy settings" - something to that effect. It's unfortunate that I'm even having to suggest this, people really should be paying more attention to what they're doing, but there's only so much you can do about the average IQ, huh!