Tomasz-
No !!! Just delete all non-free images.
It would be silly not to allow the freedoms given to us by the law to the maximum possible extent. Obviously free images (PD/FDL) are always preferable to non-free ones, but so long as Wikipedia remains redistributable AND forkable, I see no problem with using fair use pictures or those under equivalent semi-free licenses. Keep in mind that the freedom to modify is, for images, not nearly as important as for text.[1] How do you propose acquiring a free photo of a prominent, recently deceased author or actor? A picture of an important historical event? This is unrealistic -- you won't, and with your attitude, we will simply have no image for that article, while Encarta et al. will sport a nice gallery of them. Unacceptable.
Fair use is acceptable as per the current consensus on [[Wikipedia:Image use policy]]. You may use any quasi-dictatorial powers you have on pl. to enforce your point of view, but this will not be possible on en.
Having a status flag in the database would be very helpful for forkers, but we should not encourage uploading photos under licenses that limit redistribution. But a little more Linus Torvalds style pragmatism and a little less Richard Stallman style zealotry wouldn't hurt either.
What we should allow: --------------------- 1) public domain 2) FDL 3) fair use 4) free for non-commercial use. This is similar to fair use, but less vague. 5) Creative Commons licenses (e.g. Attribution) and FDL-equivalent open content licenses
What we should not allow: ------------------------- 1) Copyrighted, no permission (duh) 2) No permission to redistribute other than for Wikipedia (prevents forking) 3) Advertising or prominent copyright notices in images that cannot be removed 4) Other restrictive licenses
Regards,
Erik
[1] And before someone starts mentioning all the important crop and resizing operations we do on images, these would not constitute license violations because they do not substantially alter the source image.