Well, now we know what they're used for. (Alternate Link.)
Seriously? A federal SWAT team? Looking for a frickin' student loan defaulter? Where did she spend those student loans, SoCal Ninja Academy?
The Department of Education, originally billed as an organ to "establish policy for, administer and coordinate most federal assistance to education, collect data on US schools, and to enforce federal educational laws regarding privacy and civil rights" enforced the hell outta this guy's privacy and civil rights in the most Orwellian way possible, complete with automatic weapons and jackboots.
Look me in the eye and defend this. No, wait... imagine looking Thomas Jefferson in the eye and defending this.
EDITED TO ADD:
Don’t get bogged down in the minutiae of who allegedly issued the warrant or what offense it was allegedly for. Let’s not forget that the article was written by a reporter; they know as much about these things as they do about shoulder things that go up. Remember the Gell-Mann Amnesia Effect. Looking at the purview of the DoE IG’s office, this had to involve fraud or something, not a simple default, and I'm sure said warrant was signed off on by a judge. No doubt i's were carefully dotted and t's were painstakingly crossed on this gobsmackingly stupid raid.
The larger question is “Why does every federal agency need their own internal cop shop, to include SWAT teams, which they then have to use at the drop of a hat to justify funding?”
Saving for another day the question of the constitutionality of a federal Department of Education and the logic of them having their own law enforcement branch complete with powers of arrest, why can’t they investigate cases and then farm out arrest warrants to locals or even the US Marshal’s service? Why does every federal agency need their own tac team? Give a bureaucrat a hammer, and it’s only a matter of time until he turns and whacks you in the head with it.
The guns are just a symptom: badges come with guns, else you may as well not pass out the badges. The question is "Why so many badges?"