CanI be wiretapped without knowing? If so, how and why?

Here are the set of statutory codes on wiretapping in California:

http://www.leginfo.ca.gov/cgi-bin/displaycode?section=pen&group=00001-01000&file=629.50-629.98

Specifically, see:

629.61.  (a) Whenever an order authorizing an interception is
entered, the order shall require a report in writing or otherwise to
be made to the Attorney General showing what persons, facilities,
places, or any combination of these are to be intercepted pursuant to
the application, and the action taken by the judge on each of those
applications.  The report shall be made at the interval that the
order may require, but not more than 10 days after the order was
issued, and shall be made by any reasonable and reliable means, as
determined by the Attorney General.
   (b) The Attorney General may issue regulations prescribing the
collection and dissemination of information collected pursuant to
this chapter.
   (c) The Attorney General shall, upon the request of an individual
making an application for an interception order pursuant to this
chapter, provide any information known as a result of these reporting
requirements and in compliance with paragraph (6) of subdivision (a)
of Section 629.50.

629.64.  The contents of any wire or electronic communication
intercepted by any means authorized by this chapter shall, if
possible, be recorded on any recording media.  The recording of the
contents of any wire or electronic cellular telephone communication
pursuant to this chapter shall be done in a way that will protect the
recording from editing or other alterations and ensure that the
recording can be immediately verified as to its authenticity and
originality and that any alteration can be immediately detected.  In
addition, the monitoring or recording device shall be of a type and
shall be installed to preclude any interruption or monitoring of the
interception by any unauthorized means.  Immediately upon the
expiration of the period of the order, or extensions thereof, the
recordings shall be made available to the judge issuing the order and
sealed under his or her directions.  Custody of the recordings shall
be where the judge orders.  They shall not be destroyed except upon
an order of the issuing or denying judge and in any event shall be
kept for 10 years.  Duplicate recordings may be made for use or
disclosure pursuant to the provisions of Sections 629.74 and 629.76
for investigations.  The presence of the seal provided for by this
section, or a satisfactory explanation for the absence thereof, shall
be a prerequisite for the use or disclosure of the contents of any
wire or electronic cellular telephone communication or evidence
derived therefrom under Section 629.78.

629.66.  Applications made and orders granted pursuant to this
chapter shall be sealed by the judge.  Custody of the applications
and orders shall be where the judge orders.  The applications and
orders shall be disclosed only upon a showing of good cause before a
judge and shall not be destroyed except on order of the issuing or
denying judge, and in any event shall be kept for 10 years.



629.68.  Within a reasonable time, but no later than 90 days, after
the termination of the period of an order or extensions thereof, or
after the filing of an application for an order of approval under
Section 629.56 which has been denied, the issuing judge shall issue
an order that shall require the requesting agency to serve upon
persons named in the order or the application, and other known
parties to intercepted communications, an inventory which shall
include notice of all of the following:
   (a) The fact of the entry of the order.
   (b) The date of the entry and the period of authorized
interception.
   (c) The fact that during the period wire, electronic pager, or
electronic cellular telephone communications were or were not
intercepted.
   The judge, upon filing of a motion, may, in his or her discretion,
make available to the person or his or her counsel for inspection
the portions of the intercepted communications, applications, and
orders that the judge determines to be in the interest of justice.
On an ex parte showing of good cause to a judge, the serving of the
inventory required by this section may be postponed.  The period of
postponement shall be no longer than the authorizing judge deems
necessary to achieve the purposes for which it was granted.