| That explanation is, as far as I can tell, completely wrong. I think it's telling that it doesn't actually cite the sections of the AGPL's text that would point out the error. Copyright law -- at least, in the US -- protects both the right to distribute something and the right to modify it (technically, to "prepare derivative works"; see 17 USC ยง106 for the exact wording). Both the GPL and the AGPL grant you the right to modify and/or redistribute a covered work, it's just that the conditions that they impose are different. In particular, section 9 of the AGPL says quite clearly: > You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. And all of the other clauses of the AGPL are carefully phrased as conditions under which you may modify or distribute the work, not conditions under which you may use it. So if you simply receive a modified copy of an AGPL-licensed program and run it, then no matter who accesses it you aren't in violation of the AGPL, because you have no need to accept it. But if you are the one who does the modification, and the modification doesn't comply with the AGPL (e.g. because the modified software doesn't provide remote users with the source) then you are in violation, and it's because you did something that wasn't permitted by copyright law. |