In May 2014, Ventra - the company behind the contactless payment system for Chicago's public transport - announced that it was going to spend an hour answering questions about the service on Twitter. Ventra has been plagued with problems since its introduction (the system will be required use from July 2014), so predictably, the #AskVentra hour was hijacked by less-than-favourable queries. Here is a small selection of the tweets that were submitted...