They could be a premium publisher (who has different rules), OR they could be using another network(s) that also runs AdSense. i.e. I have used several ad networks that also run AdSense, and apparently it's within TOS if it's through a third party network.

If you look at the source code and all the ads are running the same pub code, I'd put my money on premium publisher. If they are running different pub codes, then it's probably a third party network.

Just to add to what netmeg said: It could also be that they are running ad exchange, which does allow for more units, or adsense and ad exchange together. You wouldn't necessarily see the difference without checking source. It could also be that they are just breaking the rules and not been caught.

I just checked the source code. They're running DFP through an outfit called "Grateful."

And some people wonder why we have a hyperactive thread on AdBlocking?

You can run more than 3 ad units per page if you are running them through dfp. 4 anyway. I don't know about 5.

If you're running AdSense through DFP, you can use them in 4, 5, 6, 7...there is no defined limit.

If AdSense is the only demand source that you are running through DFP the limit is the same: 3 AdSense for content units per page unless you have been specifically approved for additional units. You can have as many DFP units as you like per page, but don't serve AdSense exclusively through more than 3 of them. DFP does allow you to have additional AdSense units display on a page if these are units where AdSense is in competition with other sources.

Every time I have looked at the site I see four of the very same ads on the same page! LOL