12. Commitments and contingencies

Capital and operating leases

We lease space in managed and operated locations, primarily airports, under exclusive long-term, non-cancellable contracts to provide Wi-Fi connectivity and cellular phone access to our DAS network. Minimum rent expense is recorded on a straight-line basis over the term of the lease. Rent expense from our leases for the years ended December 31, 2013, 2012 and 2011 was $20,234, $16,760 and $15,511, respectively.

We lease equipment, primarily data communication equipment and database software under non-cancellable capital leases that expired in October 2011. The leases were collateralized by the equipment under the lease. Interest expense associated with the capital leases for the years ended December 31, 2013, 2012 and 2011 was $15, $11 and $8, respectively. We also lease office space under non-cancellable operating leases. Rent expense for our leases of office facilities for the years ended December 31, 2013, 2012 and 2011 was $1,227, $1,209 and $1,323, respectively. Included in rent expense for the years ended December 31, 2013, 2012 and 2011 was sublease income of $54, $52 and $32, respectively.

Future minimum lease obligations under non-cancellable operating and capital leases at December 31, 2013 are as follows:

Years ended December 31,	Capital Leases			Operating Leases and Airport Guarantees

2014	$	662		$	10,819
2015		383			8,830
2016		312			6,985
2017		81			5,869
2018		—			4,059
Thereafter		—			14,477


Minimum lease payments		1,438		$	51,039




Less: Amounts representing interest ranging from 1.0% to 6.5%		(439	)


Minimum lease payments	$	999




Current portion	$	526




Non-current portion	$	473

Letters of credit

In October 2013, we entered into a Letter of Credit ("Letter of Credit") Authorization agreement with Silicon Valley Bank ("SVB") for a one year term. The Letter of Credit is irrevocable and serves as a performance guarantee that will allow our customer to draw up to $1,800 if we are in default. There have been no drafts drawn under this Letter of Credit as of December 31, 2013.

Legal proceedings

From time to time, we may be subject to claims, suits, investigations and proceedings arising out of the normal course of business. We are not currently a party to any litigation that we believe could have a material adverse effect on our business, financial position, results of operations or cash flows.

Indemnification

Indemnification provisions in our third-party service provider agreements provide that we will indemnify, hold harmless, and reimburse the indemnified parties on a case-by-case basis for losses suffered or incurred by the indemnified parties in connection with any claim by any third party as a result of our website, advertising, marketing, payment processing, collection or customer service activities. The maximum potential amount of future payments we could be required to make under these indemnification provisions is undeterminable. We have never paid a claim, nor have we been sued in connection with these indemnification provisions. At December 31, 2013 and 2012, we have not accrued a liability for these guarantees, because the likelihood of incurring a payment obligation in connection with these guarantees is not probable.

Employment contracts

We have entered into employment contracts with six of our officers. These contracts generally provide for severance benefits, including salary continuation, if employment is terminated by us for substantial cause or by the officer for convenience. In addition, in order to assure that they would continue to provide independent leadership consistent with our best interests in the event of an actual or threatened change in control, the contract also generally provides for certain protections in the event of such a change in control. These protections include the payment of certain severance benefits, including salary continuation, upon the termination of employment following a change in control.