Sukey is safe
At the very earliest stages of building Sukey we had a meeting where we divided the team into groups. The groups were: Data Input, Data Processing, Presentation, Security. In other words, security has been a key issue right the way through Sukey's design and build and has received as much focus as any of the more visible aspects of the project.
The team members involved on the security side are a mix of commercial information security experts and computer nerd under/post graduates who love nothing better than a complex algorithm.
Be aware that the mobile phone service providers store a whole raft of information about your communications that enables them to track calls and texts - something they often do for the police. We have no control over the data that airtime providers keep. We understand that some people who resent corporations storing identifiable communications data chose to use unidentifiable and disposable phones, which they destroy after a protest. Sukey does not give advice on how to do this. A Google search on 'anonymous cell phone' shows that lots of web sites already exist that provide information for those who are interested to see how it works.