Even after their big facelift last year, StumbleUpon still isn’t done making changes to the their site. More and more, it seems that the social media site is paring itself down to as minimal as possible while still improving traffic and content for users. They’ll even tell you that they’re trying to create a customized Internet based on your personal interests. There’s just one catch: if you’re logged into StumbleUpon, it’s a little harder to leave the StumbleUpon experience and view the original source. Watch and listen:

As StumbleUpon makes these changes, one of the things they’ve begun to emphasize is the iframe at the top of the browser window that you use to navigate through pages as well as build up your profile so that StumbleUpon can optimize the quality of the content it funnels to you. In fact, they’ve relegated all of your activity through the iframe and guess what: you don’t have an option to remove the iframe.

If you’ve been using StumbleUpon for a while – at least before the big changes started to roll out last year – another of the things that may be apparent to you is the removal of any link that sends you back to the content sources. Unless you choose to log out and then view the site, you’re going to view the content through StumbleUpon whether you like it or not.

Brent Csutoras, writing for SearchEngineLand, noted the lack of controversy within the tech industry concerning this change. “When Digg did the same thing by launching their DiggBar,” he wrote, “the tech industry was up in arms and the DiggBar even had an option to close” – an option not available here with StumbleUpon’s new change.

At any rate, StumbleUpon’s giving you a little less flexibility when it comes to opting out of viewing content through their filter. Have the changes affected how you use StumbleUpon at all? Did you even notice? Let us know in the comments section below.