In all seriousness, look at recently updated apps. Earlier today we had someone that was using an app they thought to be trustworthy and come to find out a recent update added ads to this app. Once they removed this app wit the undesired additions, the ads went away.
OP: The playful replies are because you used the word "illuminate" instead of "eliminate". Of course, you have every right to do this. I myself like to refer to snakes as "serpents", á la Bible.