1. in the foreign film "Raid 2," the undercover police officer, frequently removes the sim card from his one smartphone and inserts a second sim card in order to have: a. one isolated network for police communications; and b. one isolated network for criminal communications. 2. all across america, many people own/possess and carry two smartphones: a. the one issued by their employer for work; and b. the second purchased by the user for personal communications. 3. the reasons for "2," vary, but primarily relate to the employee desire to keep his/her personal life segregated from employer supervision. ... the inconvenience of such activity becomes obvious. 4. hence, the questions arise, ....; does android software and/or related mobile phone hardware admit of: a. simultaneous installation of and switching between two sim cards (on two different networks and/or telephone numbers) in one smartphone?; and b. segregation and isolation otherwise, of personal and work data/communications in a single smartphone. 5. by way of example, i installed three email accounts on my android phone: a. one for work on exchange software; b. one for personal on android software; and c. one for the device itself, gmail, because android likes to have a gmail account to deal with. this arrangement however, nontheless integrates all contacts via the phone contact file; and hence, becomes unacceptable, and mandates removal of office or business email account. hence, a separate question; does android permit meaningful segregation of email accounts?