I locked my bike under the bridge at the clybourn metra stop for fear that it might rain today. I locked the bike at 8am to a solid metal bike rack on Ashland Ave. under the bridge at the clybourn stop. While locking my bike to the rack, a man dressed in khakis, white t-shirt and tie asked if would be okay to lock his bike to my cable (used in conjunction with my U-lock for securing rear tire). He mentioned he was going downtown for an interview and would be back in a few hours. I said no problem as he had a mini U-lock and looked as though he was frustrated trying to fit it on a nearby poll. My bike was secured through the front tire and rim as well as with the cable lock thru the rear tire and frame. I am not sure if this person is related to bike being stolen or if his bike was also stolen, he had an old schwinn. I returned to the scene at 5:42pm only to find my bike missing, as well as the cable and U-lock no where to be found.