This paper reports results from an online survey on the impact of travellers' privacy and security attitudes and concerns on their willingness to use mobility-as-a-service (MaaS) systems. This study is part of a larger project that aims at investigating barriers to potential MaaS uptake. The online survey was designed to cover data privacy and security attitudes and concerns as well as a variety of socio-psychological and socio-demographic variables associated with travellers' intentions to use MaaS systems. The study involved $n=320$ UK participants recruited via the Prolific survey platform. Overall, correlation analysis and a multiple regression model indicated that, neither attitudes nor concerns of participants over the privacy and security of personal data would significantly impact their decisions to use MaaS systems, which was an unexpected result, however, their trust in (commercial and governmental) websites would. Another surprising result is that, having been a victim of improper invasion of privacy did not appear to affect individuals' intentions to use MaaS systems, whereas frequency with which one heard about misuse of personal data did. Implications of the results and future directions are also discussed, e.g., MaaS providers are encouraged to work on improving the trustworthiness of their corporate image.