I also lean toward the interdimesional theory as an explanation for why there are so many blurry photographs. Think of an analog radio dial... if a station broadcasts at 105.9, you can probably pull the signal in on 105.7 or 106.1, but the sound won't be clear and crisp. The things being photographed are on a frequency close to the one we are tuned to, but off just enough that we can't get a perfect signal. Not to say they are never on the same frequency as we are, however.
As for photographic evidence, the fakers are just too good these days for the layman to tell a fake from something genuine. There are ways to detect fakes, but you need to know what to look for, and sometimes the fakery is so good that digital forensics are needed to root it out.