I found A JUICY COUTURE Velour Basic Hoodie on piperlimes website (its part of Gap, old navy etc.) that had no price I put some in my cart and placed an order which came out to free for those items. The company called me today saying it was a mistake and there canceling my order, is there anything that I can do to fight with them?

Nope they don't have to do. Its more of a customer service type of thing when companies honor price mistakes. Sometimes companies will give like a 5-10% discount for the trouble Also, a lot of websites have disclaimers saying they can cancel an order even after you purchased it when shopping online.

Sgt is right. If you call and complain to the customer service department (be careful how you handle it. If you start rude they'll be less inclined to want to make you happy.) you might be able to get it discounted or something like free shipping on the rest of the order. But they aren't require to.

Use of their site constitutes agreement to the terms of use that they have posted.

The section on Site Transactions states:
"We reserve the right to refuse any order you place with us. We may, in our sole discretion, limit or cancel quantities purchased per person, per household or per order. These restrictions may include orders placed by or under the same customer account, the same credit card, and/or orders that use the same billing and/or shipping address. In the event we make a change to or cancel an order, we will attempt to notify you by contacting the e-mail and/or billing address/phone number provided at the time the order was made. We reserve the right to limit or prohibit orders that, in our sole judgment, appear to be placed by dealers, resellers or distributors."

Additionally, the section on Errors, Inaccuracies, and Omissions states:
"Occasionally there may be information on our Sites that contains typographical errors, inaccuracies, or omissions that may relate to product descriptions, pricing, promotions, offers, and availability. We reserve the right to correct any errors, inaccuracies or omissions and to change or update information or cancel orders if any information on the Sites is inaccurate at any time without prior notice (including after you have submitted your order)."

You can always hire a lawyer if you can find one that will take the case, but I think you would be on weak legal footing. Plus, who expects to get something for free in a capitalistic society?

In the UK this would come under the distance selling regulations and they are bound to honour the advertised price. E&OE is no defence in law..

That being said they could simply turn round and say that it is out of stock or discontinued and therefore cancel your order in that manner.

You always have the option of small claims to sue them, but you will most likely lose.