I remembered getting 'harassed' trying to clear CGK departure immigration. The fella just did not want me to pass thru and clear my passport. He kept turning pages and asked me a lot of vague and unnecessary questions. In the end I slipped SGD2 into his hands and in a flash he stamped my passports and let me go.
Another documented 'immigration' story occured at the Causeway checkpoint from Johor Bahru Malaysia, this guy filled up his car with petrol at a nearby gas station. This gas station accepts payments at the gas pumps itself without any receipts. After that he drives to the nearby checkpoint to re-enter SIN, but as he stopped at a passport checkpoint, an 'official' from the gas station tapped on his car window and told him that he left the gas station without paying. The driver protested, and the official asked for a receipt. But since he did not have any, the 'official' complained to the immigration officer that the driver has committed an offence an the police needs to be called in. The driver agreed. However after awhile the immigration officer and the gas official continued to hassle the driver,threatening to jail him, impounding his vehicle and passport. Giving up the driver paid the gas official the money for the 'petrol'(RM40) and an extra 10 for inconvenience. As he drove away , he turned back and saw the gas officials shaking hands and taking a cut of the payment.
Cheers!