[arst]

If I copy GPL-licensed code into my BSD-licensed library, none of my code has to be relicensed.

Yes it does, that's a pretty central feature of the GPL. See section 2.b. of the GPL (v2):

b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.

[jmillikin]

You forgot the very next paragraph:

These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it.

In other words, my code remains mine. I still control the copyright to it, and do not have to relicense it.

[arst]

Those conditions don't apply because Google is accused of distributing a derived work. If Google is distributing a work derived from GPL'd code then they can only distribute that work under the terms of the GPL. There's a lot of debate over whether what Google's distributing can actually be considered a derived work, but that's a separate question entirely.

[JulianMorrison]

It hasn't been re-licensed. It's just not lawful to distribute.