Ghost bikes taken down?

Advance apologies: new to the community. 

A while back in December I was biking to various ghost bike locations. A friend of mine started cataloging personal stories and encounters with ghost bikes in San Fransisco and I was looking to do the same in Chicago. I found a lot of ghost bikes up north still up, but a lot of the south-side bikes seemed to have been taken down. I was told by a Steven from streetsblog Chicago and Oboi from Slow Roll that usually the city policy was to have a hands-off policy, so I'm guessing that these were perhaps taken down by local establishments. (The ones I visited were Hector's at Western/Ogden and Frederick's at 18th and Racine). If anyone can shed some light on this, let me know.