Ad-block application have been controversial since they emerged.<br />Now, some are suggesting ad blockers could lead to the downfall of the World Wide Web.<br />And Yahoo is at the center of annoying from ad-block apps.<br />Apparently, Yahoo is actually stopping some Yahoo Mail users from checking their e-mail if they have installed ad-blocking software in their browsers, according to reports.<br />“At Yahoo, we are continually developing and testing new product experiences,” Yahoo spokeswoman Anne Yeh said in the statement.<br />Last week, users began reporting they were being blocked from accessing their Yahoo email inbox for using an ad-blocker without warning.<br />Yahoo confirmed reports that it is preventing a few Yahoo Mail users from seeing their e-mails until they turn off their ad-blocking software.