RockYou

you need to be added by the user via the "my friends" tab in order to see their slideshows, then you show up in their "my favorite people" [http://www.rockyou.com/subscription/my_favorite_people.php] and "fans" [http://www.rockyou.com/subscription/my_fans.php] tabs.
so at any point, even if someone found a way to do it, you could be removed by the user once they noticed.
here is the js for removal, which i know nothing about.
javascript:fan_delete([your user id], [target user id], 'If you remove this friend, they will also be removed from your favorite people list. Continue?', 0);
on top of that, the user must "share" the slideshow in order for another rockyou user to be able to view it. if they do not have this option enabled, you won't be able to view it, even if you are a friend or a fan.
here is the url for sharing a slideshow:
http://www.rockyou.com/show_my_gallery2.php?instanceid=[rockyou slideshowidhere]#
now, all you really need is to be on their "fan" list [http://www.rockyou.com/subscription/my_fans.php], because rockyou describes that page as: "These RockYou users will be notified when you share a new slideshow", but, you are automatically put on both lists.
now, do you know their rockyou id by any chance?
http://www.rockyou.com/viewprofile.php?useridreq=xxxxx
that url will take you directly to their profile.
if the myspace, or whichever site they have the slideshow hosted on is accessable, you can either hover over the slideshow to get the slideshow id, or i used Firefox and went to tools-page info.
my rockyou slideshow is on my MS account, so i looked thru the links, and the rockyou slideshow had been converted to MSlinks [http://www.msplinks.com/MDFodHRxxxx= ].
now here is something interesting...i wasn't logged into my rock you account in that browser, and it took me directly to this:
http://www.rockyou.com/slideshow-create.php?refid=[slideshowid]&source=cyo
now it's a page to add photos and edit the slideshow, it let me upload a pic to add to the slideshow, now i didn't save my changes, because i didn't want to screw up my slideshow. but all the urls indicated that i was editing the slideshow from my myspace page, same slideshow id and everything. this seems like more of a direct "IN" to me then trying to add yourself to the fans, and blahblah. it may let you do the editing but once you try to save or view anything, prompt for a password, not sure.

i am dog tired, and can't create another slideshow to fiddle with and edit right now. but it definitely seems like there is a window of opportunity there if you can get a slideshow id number from the ms page. try hitting up the "anyone willing to add my target" thread, or create a fake you think they will add if you need access to that info.

log in to your rockyou account, then go to the friends link in the upper left hand corner next to your profile pic. then it will want their email address. plug it in. their name will show in orange if they are a member, then check the box that you want them to receive updates. they will get email notifications when you add new photos/slideshows. when you add a friend, they receive updates about you. i believe they have to search for you and add you if you want to look at their photos. so, if that is what you are looking to do, you may need to be asking a different question...if you know what i mean

however, by default in rockyou, the account is set to public (which i didn't realize when i went to log in just now). so for about 9 months now, anyone could've been snooping thru my account!

i was so busy making my slideshow, i didn't bother to go into ALL of the options (i'm a GuGer now, and i know better....so now it's private!).