Based on the context and the answer, generate a question. 

Context: The logistical and technological hiccups of the first twenty - four hours got sorted out . I wish I 'd been able to explore Mountain View and the surrounding area a bit more ( there are some good quilting shops around apparently , though none in San Francisco ) but as I wo n't drive ... Next time I travel I will tell the bank in advance so they do n't cancel all my cards again . I will also make sure my phone service provider has set up my account correctly .

Answer:

They thought someone stole their card .



Why did their bank cancel their cards ?