yea i think there is a way,but works in certain versions of yahoo though,but it works 4 me
method:
When you try to access another user’s shared files, you will get a pop-up
with a message that either reads “Asking for permissions” or “user offline”.
Even if the user is marked Invisible, you will still recieve a message
confirming that the user is online and is being asked to allow you
permissions. So even when your friends look like they are offline, right
click on thier name and select “View Shared Files” to find out for sure!
Yet, if the user is online in invisible mode and you
ask for his shared files, he will likely get a pop-up
telling him that someone is trying to access his
files. This probably depends on his security
preferences.
So yes the it works, but you might be letting
know your “victim” that you’re after him.