Twitter is awash with reports of Boris Bike stands having to be manually rebooted.
Ross Lydall, chief news correspondent for the London Evening Standard, tweeted:
"Breaking news: #Borisbikes chaos as system collapses at start of casual use. Terminals need to be rebooted manually. #Serco in v hot water."
Later, he wrote: "#TfL says 100 #Borisbike docking stations crashed at launch of casual use. Now down to 68 broken as #Serco gets b*llocking."
Serco is the service company charged with running the London Cycle Hire scheme.