Online indicators

A question I've pondered for a while.. how do online indicators work? You know the objects that some people have in their stores etc that show whether they are online or off?

Does the owner put his or her UUID in a script and if so, what stops anyone from using anyone elses UUID in such a script to check whether they are online or not?

Most standard (and free) online indicators just go off the owners name.

Some advanced ones say the online group indicator uses UUID's.

But whats the point in putting someone elses UUID in it? Can't really harass them unless you're weird and like msging people saying "I see youuuuu"

then its just an easy mute

They work something like that.

And nothing..nothing at all. Some places even sell devices that will notify you if someone else (whom you determine of course) comes online.

Personally...I've been trying to script a dual online indicator for the missus and I. One that displays only my name when I'm the only one online, her name when she's the only one online, and our last name for when we're both online.

Having a devil of a time with it though.....

Yep. As soon as you have someone's key (UUID), you can always check if they are online, using:

llRequestAgentData(key, DATA_ONLINE);

There are several websites to look up resident keys by name (). Nothing stops a scripter from checking on any SL resident, no matter if they want to be seen or not. It's impossible to be really invisible or to have any privacy on the grid (something LL needs to change, imho).