(CNN) -- Anytime you tinker with something that millions of people use daily, you're going to upset some folks. Remember those redesigned $20 bills a decade ago -- the ones people said looked like Monopoly money?
Scott Sanders began an online petition protesting the new Facebook. It now has more than 1.5 million names.
That may explain why Facebook's new makeover is sparking strong opinions -- hysteria, even -- among the more than 100 million users of the popular social-networking site.
More than a week after Facebook began forcing users to its redesigned pages, a backlash is still rippling through the online community.
"The new version is cluttered and there's no continuity to it," Valerie Stayskal of Addison, Illinois, told CNN. "I don't like the tabs they've got. When you get to the news feed, you see all these fonts, and it's just a mess. Very hard to navigate."
"Some of these [changes] just seem kind of pointless. The reason I joined Facebook is because it was simple and easy. Now they're just making it more complicated, and I really don't like that," said Kyle Aevermann of Gilbert, Arizona, who sent his complaints to CNN in an iReport video. "I just wish they would have kept it how it was." iReport.com: Watch Aevermann's Facebook review
Facebook's new look separates users' personal profiles into different areas of the site and provides more tools meant to make it easier to share information and photos. The changes also shift users' applications to the bottom of their home page and create more white space -- a move some users fear will lead to more ads on the site. iReport.com: What do you think of the new Facebook?
Facebook unveiled the makeover in July and let users decide whether to switch over to the new format or keep using the old one. But that transition period ended almost two weeks ago, when Facebook eliminated the previous version. Users logged on to the site to discover the information on their personal profiles had been rearranged.
"We are just beginning the process of moving people over to the new Facebook and saying goodbye to the old Facebook," wrote Mark Slee, product manager for Facebook, in a September 10 blog post on the site. "We set out to make Facebook simpler, cleaner, more relevant, and easier to control. With your feedback and participation ... we believe we've gotten to the best Facebook yet."
But many users don't agree.
In the past week, CNN has received more than 200 unsolicited e-mails from people complaining about the new Facebook. Several online petitions are circulating that urge Facebook to give users the option of returning to the old format. One, Petition Against the New Facebook, was launched by Scott Sanders, a student at Austin Peay State University in Clarksville, Tennessee, and has more than 1.5 million names.
"Facebook was once the classy alternative to MySpace. Now it's the classy girlfriend you once loved, but you begin to feel distant from because she wants to move into your house and tell you what colors to paint your walls and how to arrange your furniture," said iReporter Sara Campbell, 26, of Louisville, Kentucky. "You're given an ultimatum -- marry me or it's over. I wonder how many of us will give into the demands?"
Many other users defend the new Facebook, saying they find it better organized and easier to navigate.
"Quit your whining. It just takes time to get used to. You just have to be patient," said iReporter George Topouria of Tbilisi, Georgia. "I actually like the new design. It may seem to be giving less information on one page, but at least it doesn't take a century to load."
"When a company like Facebook doesn't change, it leaves open the possibility that one of countless other social-networking sites will make the changes that Facebook didn't," said Zack Colman, 24, of Los Angeles, California. "For those of you who don't think the Facebook system was broken, consider how hard it was to sift through all of the applications on someone's page before finding the relevant information you wanted. Or even just to write on their wall. Now, what you want is right in front of you."
In a September 18 blog post on the site, Facebook co-founder Mark Zuckerberg said that almost 100 million people around the world are now using the new design.
"It's tempting to say that we should just support both designs, but this isn't as simple as it sounds. Supporting two versions is a huge amount of work for our small team, and it would mean that going forward we would have to build everything twice. If we did that then neither version would get our full attention," said Zuckerberg, who launched Facebook from his Harvard University dorm in 2004.
"That said, Facebook is a work in progress," he said. "We constantly try to improve things and we understand that our work isn't perfect. Even if you're joining a group to express things you don't like about the new design, you're giving us important feedback and you're sharing your voice, which is what Facebook is all about."
The recent makeover isn't the first time Facebook has seen its users protest a change to the site. In 2006, the Palo Alto-based startup angered users by introducing a tool called "news feeds" that automatically broadcast users' personal details.
That furor eventually waned. Facebook is counting on this one subsiding as well.
"The new Facebook may upset a lot of people at first, but eventually we will get used to it and probably enjoy it more than we used to," Colman told CNN. "I'm sure in a few weeks everything will die down and in a few months everyone will have forgotten completely about the old Facebook."