  Another set of worries affecting opacity/non-transparency arise because search engine companies do not always disclose, either fully or clearly, their practices with respect to two important points: (i) whether (and to what extent) they collect information about users; and (ii) what they do with that information once it has been collected. These kinds of opacity/non-transparency concerns involving search engine companies, which are also related to privacy issues affecting monitoring and surveillance, are examined in detail in  Section 3.3.