To answer the original poster, Yes people are cheating Match fishing. The most common way is by use of Macro Mice. This is a program that allows for a series of keystrokes and effectively dials the timing in perfectly allowing for consistent high weights. SL currently has 0 detection tools available as they have made it so the dis honest are now more protected than the honest. With that said...Click pattern and frequency, bot-like mouse movements, player interaction, anti-random attempts, afk/away status, are probably the more common methods of detection.
*Edit* This method may take out some actual people but they would be the rude ones that never speak or interact etc. So that is a personal call as to it being a loss or not*