Depends on what "we" we're talking about.
The congressional DVD documents/presentations prepared by Stephen Greer's DISCLOSURE PROJECT might constitute convincing proof in a lot of court rooms.
Of course one must be skeptical and discrimminating.
The the naysayer's knee-jerk response is the well engineered parallel/puppet jerk carefully crafted by decades of disinformation; partial truths; etc. by the powers that be. Following THAT LINE gahgah hook line and sinker is not any more admirable than accepting all the fringe stuff as gospel.
AND YOU KNOW IT.
But go ahead. Enjoy the TYPE II error as long as you can. It's days, on this topic, are rapidly getting fewer in number.
I don't know why, but Dr. Greer consistently puts me to sleep. I've never stayed awake more than 10 minutes into one of his interviews. If he comes off the same way in a court room it won't help the cause, even if the material presented is compelling.