Back in the early eighties if you were searching for evidence of intelligent life elsewhere, one was pretty much limited to blind faith,  and if you could not remember your own, having to rely on the word of other peoples UFO, angel, out of body experiences.
But ET is extremely clandestine and although
the evidence for the critters is out there. It is accumulative, there is no one proof.
Then came crop circles. Obviously there source is different to ET because ET continue to be clandestine in their activities. Whereas the circle makers are blatantly open and obvious in your face. Though strangely unable or unwilling to make their agenda too obvious. 
Hoaxed circles are certainly real and are a real problem and pollute the evidence
But there still remains some Summer circles that are unhoaxable which are absolutely undeniably 100% proof of the true reality of non homo sapiens intelligent communicators.

Just look at these pictures.
Just a view across a barely field right?
Wrong these are both views from the middle of the 2000 Seaton crop formation in Leicestershire. All the affected plants are three to six inches shorter than the unaffected plants.

           !! UNHOAXABLE !!

Next take a look at the aerial photo |here| of a circle from Noyan, Quebec. The circle appeared in the middle of a field of 9 to 10 feet high cattle corn. There are no tractor lines in the field. Making it absolutely impossible for any one to enter the circle undetected. There is absolutely no way in (or out) of the formation except from a helicopter without leaving an obvious track (which there are absolutely none) in the crop.
                                                                                      !! UNHOAXABLE !!
 

Next take a long and careful look at the anomalies section of Janet Ossebard's Beautiful and excellent web site.
circularsite.com
                                                                     !! UNHOAXABLE !!

As the above are all impossible to hoax then one is left with only 1 extra ordinary explanation as to the authorship of at least some of the crop circles world wide

 WE ARE NOT ALONE

If we can open our minds enough to accept that truth.
Then we should listen to what 'they' want to say to us.