You thought they were gone. Those pesky, annoying, experience-destroying things. Yes, I’m talking about iFrames.

Popular a decade ago, they’ve made a few appearances in the past several years. The once-popular Digg, for instance, turned to them to implement its DiggBar.

But now they’re back.

As detailed by Brent Csutoras on Search Engine Land, the company responsible for bringing them back is popular social discovery service StumbleUpon:

…on all content pages within StumbleUpon, you have a single button saying ‘Stumble This’, which when clicked takes you to an iframed version of the content.

Not only are they now iframing all content from the site, but if your logged into StumbleUpon, they are not even offering a way to remove the iframed toolbar, leaving you in stuck in the iframed version of the site. If you are not logged in, then there is an option to click X in the right side of the toolbar to remove it.

Csutoras observes that there hasn’t yet been an uproar about StumbleUpon’s change, despite the fact that iFrames have caused so much angst before. In the case of the DiggBar, to placate angry users, Digg founder Kevin Rose was forced to backtrack and admitted, “Framing content with an iFrame is bad for the Internet.”

Is the lack of widespread anger here an indication that StumbleUpon’s relevance has declined? Perhaps, even though unique visitors are apparently way up year-over-year. But regardless, there are more than a few publishers who still get a meaningful amount of traffic and link love from StumbleUpon. And they can’t be too happy about this.

At the end of the day, you have to hand it to the iFrame. While it does have uses, it has arguably been one of the most abused ‘features’ of HTML. But you can count on companies ignoring internet history and using it in the worst ways imaginable.