My buddy list is funny because I've kept the same screen name since middle school [veela7, an obscure Harry Potter reference] and have never cleared away the contact information for buddies with whom I have not kept contact.
Once I started using Mac computers and iChat, I delighted in my ability to rename the people on my buddy list. With the very last shreds of memory as to who these people were to me, I altered their screen names as they logged on to AIM, and the results were pretty fucking mean.
Most of my unacquaintances' screen names were changed to their full names with some sort of comment. Some people received an adjective in quotations between their first and last name, the way you would include a nickname when credit your fun coworkers. Except that these nicknames are "crazy" and "oh christ." One girl who was labeled "oh christ" had done a lot of missionary work over summer vacations during high school. I later labeled a second and third girl "oh christ," but at that point I was just being expressive and trying to maintain a level of continuity. For one young lady, who often complained of illness, and whose last name I had forgotten, I wrote her first name and then added: "I just got out of the hospital" w/e her last name is.
Some people have screen names that are worse than mine, so sometimes I'll put their full name and then add, "but his screen name is ThePoetGod" or "whose screen name means Life Sucks So Kill Yourself."
Some people on my buddy list had passed through my life as would an insurance commercial, somehow louder than the television show I was watching and repeated just enough times throughout the half hour so that I can't totally forget. Others had impacted me in a way not dissimilar to painful dental work that I could have survived without, and whatever stress they caused me was probably later taken out on a customer service representative. The former were nicknamed "who?" or had had "like it matters" added to their surname. And the latter buddies received titles like a dentist would, following his full name with DDS. First name, last name, "could have been worse." First name, last name, "or some asshole like that." First name, last name, "is nothing sacred."
For one girl, I filled in her name and then her actual title: "NY Jets Girl Next Door!"
99% of people with whom I have some contact do not get unflattering nicknames, even if we don't regularly speak online, even if you deserve it. My fear of you someday coming over, or somehow seeing what I've titled you on my buddy list when we attempt a file transfer, is so great that I will leave you at your full name.
The 1% getting made fun of and still talking to me are people whose AIM interactions with me are very bothersome. They are not the type to be here, reading this now, but they will IM me from time to time and sexually harass me or ask probing things. In turn they were nicknamed something foreboding, like "eek" or "oh no!!" Through file transfers with them, I'm almost sure that they don't know that I make fun of them, but I still don't want to risk it more often.
I have to get my ya ya's out with my buddy list because I had to stop making fun of people in my phone. One afternoon I hung out with a girl who then realized she couldn't find her phone and asked to use my phone to call herself. She dialed her own number and pressed the green button, and then her nickname appeared on the screen, a slightly hurtful alliteration with her first name. I explained, grinning stupidly, that I had a lot of girls in my phone with the same first name, so they all received negative nicknames; I guess she forgave me because she liked being my friend, but things were probably different after that.
It's easy to see that I can't afford to lose friends here in Los Angeles. It's hard for me to communicate with people out here; often, kids don't know when I'm kidding. They'd sooner respond to a vague compliment than a joke, even if the latter is my sincere way of offering companionship. Should I ever be cunning enough to confuse an Angelino into coming to my apartment to hang out with me, I'll probably just leave my iChat logged out.