Oh, honey. If you think keeping tabs on exes through the magic of the internet is "cyberspying" or "cyberstalking", you are really not prepared for the World of the Internet, are you.
Let us go down the list.
Z, preschool: I located him on Facebook at one point, but didn't add him as we really didn't have much contact with each other in high school, which was where we re-met.
J, 1st grade: Good luck even finding a common name like that on the internet. Plus we really didn't have much of a relationship, just me with a crush on him.
J, 1st through 5th grades: I don't think he has an internet presence, but I correspond with his sister (who is my birthday-twin) from time to time.
"Kermit", 6th/7th-ish grades: Yeah, I Googled him up a while ago, found out he was having some awesome times, started e-mailing back and forth.
"Bugs", 9th grade: Savil was trying to find him, but she doesn't seem to have had any luck. I really have no desire to re-open that connection, not even to chatter.
"Scott", 9th grade, massively unrequited: Every now and then I try and Google him, but he has a double whammy in the anonymous department: a common name that also has a famous person sharing it. I'd like to say hi and wish him well and see what he's up to. Out of everybody, I think I've devoted the most time and energy to attempting to track him down.
pyrogenic, 1995 and 1996, unrequited: Notice how there's a mutual LJ friending going on. We occasionally run into each other locally as well.
brooklynmili, 1995 and 1996: Also mutual LJ friending, though we found each other on Facebook (through Josh) first before connecting through X-Files on LJ.
H, 1996? 1997?: Every now and then I search for her. I wish we'd kept in contact, but she has her own priorities.
Good Old Shawn, 1995-1999, g-d help us all: I know who and where he tends to be online, we have each other's numbers, but for the most part we do our own things.
The Drunken Computer Science Major, 1998: I think I tried Googling him some time back, maybe, but didn't get anywhere. I have no real attachment in any case.
"River", 1999-ish: We have each other added on MySpace; I should probably poke him sometime, say hi, see what's up.
BJ, 1999-ish: He's blocked on any form of contact of mine that he had that I knew of. I got some gossip about him through another ex of his a while ago, but my only real interest in him and his life is so I can keep it clear of mine. I want him to have never existed. I would be happy if his parents had never met. I think I occasionally try Googling for obituary records on him just in case he's dead now.
digitalambiance, 2001: Mutually LJ friended, but he doesn't use his LJ much these days. I really have no desire to search for what he's up to, and in any case he did just ping me the other day with news.
Y, sometime between 2001-2005: After the Incident, I cut contacts. I think once in the past few years he came to my attention again (interacting with a mutual friend), and I looked at his LJ, but I had no desire to stealthily subscribe in any fashion.
marxdarx, a weird affair sometime in the 2001-2005 range: Sometimes I Google him to see if there's more trainwreck. I am not adding him back on Facebook, though. I quite sweetly and sincerely wish him the hell away from me and mine.
Figment, 2005: Mutually LJ friended, but he doesn't use his LJ much anymore. Sometimes he pings me; I don't pry.
My best friend, 2001-present, unrequited: No need to Google him; he has no public internet presence to speak of (I'm the one among his close friends who does not pester him to get a Facebook account), and we talk regularly so there's no need to in any case.
My hobby-related habits are such that while the amount of time and effort I put into a single round of searching is nothing short of alarming, the fact remains that I will do this for any topic, and not just an ex. On the whole, I spend more time and energy attempting to track down suspected spammers, scammers, and other internet lowlifes (both in total and per individual) than I do trying to track down exes. Generally I either know who they are online and what they're up to, or I just don't want to know.