Take a look at the new data protection Directive from the UE (will be in effect from June 2018) - Eventually all states will have some kind of regulation simila

Take a look at the new data protection Directive from the UE (will be in effect from June 2018) - Eventually all states will have some kind of regulation similar to this: http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:OJ.L_.2016.119.01.0089.01.ENG&toc=OJ:L:2016:119:TOC http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:O... The best way to comply if your app is used in Europe is 1) start writing a .doc document detailling which data you want to collect, where do you store it, when do you use encryption (suggestion: both in the application and the data volumes - but be careful choosing the ciphers for volume and in-app), and why do you allow people to see the data.