Quoting Hendrik Boom (hendrik@???):

[Re-user of LGPLed code revealing his source code or submitting
very reverse-engineerable object code:]

> The incorporator can do either of these things. He can also
> distribute obfuscated object code. The only thing he has to permit is
> linking with the independently written lgpl library.

Caution: You cannot determine what a code reuser can and cannot
(lawfully) do by reference to the text of a proprietary or open source
licence (LGPL or other), nor by reference to FSF's FAQs, for the simple
reason that this hinges on a key legal concept, 'derivative work', that
is defined by copyright caselaw. It is defined by the courts, and FSF
doesn't get a vote.

FSF materials argue that this-type linking creates derivative works,
whereas this-type linking does not. Unfortunately for this opinion,
nothing in caselaw so far has supported this view, and I warn that FSF
materials' legal claims tend towards the aspirational: They reflect
the way FSF would like decisions to come out, which is not necessarily
the same as reality.

To understand what 'derivative work' means for software and other
copyright-covered works, there's really no alternative but to do enough
reading to have basic understanding of copyright law, e.g., read one or
two of the credible books on open source licensing. I'm fond of Larry
Rosen's book _Open Source Licensing: Software Freedom and Intellectual
Property Law_, which is available online in PDF, but there are others:
http://rosenlaw.com/open-source-licensing-software-freedom-and-intellectual-property-law/
And it couldn't hurt to read some of the key caselaw. For USA
jurisdictions, I link to key texts from
http://linuxmafia.com/kb/Licensing_and_Law/ .