This has been reported several times. Here's a photo of what could happen - this bridge in France is collapsing under the locks.

City of Oakland Public Works Department addressed this issue on 06/16/2015, service request # 586263.

Thanks for fixing this issue!

Open

The issue was closed without being fixed.

The City of Oakland Public Works Department has received this issue. It is registered as service request #587282. Please check back for status updates, or contact us directly at 510-615-5566.

If the locks are left, and new ones added, the City of Oakland may end up having a problem like that of Paris, where the weight of the padlocks endangers the structural safety of the bridge(s) the locks are on. Can the city at least check to see that this is not a possibility, if it doesn't want to remove the padlocks?
Please re-open the issue if it was, indeed, closed.

City of Oakland Public Works Department addressed this issue on 07/06/2015, service request # 587282.

Thanks for fixing this issue!