Using disposable emails and burner phone numbers could be part of your privacy system. Using disposable emails in replying to dubious sources may be a great idea, protecting your real identity from SPAM and perhaps worse. Likewise doing the same with burner phone numbers, perhaps for a blind date or other connection where it is not initially known how things might go. Protect yourself from being stalked or truly identified. This DOES NOT protect your physical phone from being identified by sophisticated or determined adversaries.
Solutions to consider include:
Burner Phone Numbers
From iPhone App Store or Google Play, consider such products as Burner, LoudCloud and Shuffle.