One day you’re up, the next day you’re down.

Just yesterday, we were gushing over the rapid rise of online coupon provider Groupon. Frank pointed out that Groupon had managed to achieve a $1 billion valuation, despite the many copycats in the marketplace.

Well, one of those copycats is not prepared to go quietly into the night.

According to GigaOm, Tippr picked up a boatload of patents that could put a serious dampener on Groupon’s capital raising efforts.

[Tippr CEO Martin Tobias] saw the rise of Groupon. He happened to know that Microsoft co-founder Paul Allen, who’d invested something like $90 million in the failed Groupon of the late ’90s, Mercata, still owned that company’s patents.

In exchange for equity in Tippr, Tobias picked up 12 patents which cover everything from “Attaining product inventory groupings for sales in a group-buying environment” to “Demand aggregation through online buying groups.”

Of course, Tobias is quick to distance himself from any speculation that he’ll use the patents for anything other than as a “defensive weapon,” but simply owning the patents puts Tippr in an offensive stance. A stance that all of a sudden doesn’t quite make Groupon look so golden.

Will we see a patent infringement suit from Tippr? Perhaps, but certainly that will come AFTER Groupon earns its $1 billion valuation. And it may not even come until Groupon is either acquired by [fill in the blank] or files for an IPO.