Innovatio IP Ventures, LLC (a company formed in early 2011 for the purposes of acquiring, licensing, and litigating patents for royalties) purchased a number of patents that, according to Innovatio, encompass certain WiFi and WLAN technologies.  Innovatio has been busy filing complaints against the likes of Cosi, Caribou Coffee, Panera, hotels, grocery stores and other entities that, for example, provide WiFi for their retail customers.  Innovatio has also undertaken a broad letter-writing campaign, advising recipients that they may be infringing and inviting them to enter into a fee-based license (or potentially face a lawsuit).  Cisco and Motorola have entered the fray, filing a lawsuit against Innovatio.  Certain defendants have filed a stay while the Cisco / Motorola lawsuit is resolved.  You can read more about that lawsuit in the motion to stay, which also gives a great overview of what Innovatio is asserting.

It might be a good time to check the indemnification provisions in your purchase agreements relating to WiFi and WLAN technologies.  Here's an article that describes about how to contractually protect against patent trolls.