Someone who comments on everything the said stalkee does on Facebook, ie status change, quiz results, new pictures, within one minute of uploading.
An fb stalker is unwanted by all, and should be treated with great caution as they know when you have blocked them and them only because they ask other people if they're blocked also.
1. "Bloody hell, I can't upload ANYTHING without Dylan commenting something lame on it first, he's turned my page into a fucking comment repellent now!"
2. "You just know she's sitting there waiting for my reply, that last one took under a minute, when did she turn into an fb stalker?!?!"
You'll know when it happens, so heed my warning!