Certainly not, presuming it doesn't escalate to the level of trademark/service mark infringement (to be fair, IANAL). Just a risk consideration...your product, your call.
But I think there's value in at least recognizing that the namespace is quite crowded given the collisions that two interweb randoms were able to identify in short order.
I would argue that every known noun are the first domains to get registered. My goal is to associate workplace search engines with haystack.