Safety of iPad battery on air flight

I am flying to Canada from the UK shorty and have noticed that the safety of Lithium batteries is mentioned in Air Transat's list of restricted and/or prohibited items. The advice, however, is a little vague for items such as iPads, cameras, etc and I really do not want to have my iPad confiscated at security check-in!

Does anyone have experience (good or bad) of this? With a camera all I might loose is the removable battery but with an iPad its not only the battery but also the device and all that it contains!