[Accipitriform]

It's not happening much at all in NFL football, since it's a major penalty if caught, and it's hard to hide.

I do hope helmet technology improves to handle inadvertent contact.

[melq]

Disagree, it happens all the time. Its a 'major penalty' in that you get fined many thousands of dollars, but I'm pretty sure the team pays it anyway, and that is a drop in the bucket.

http://bleacherreport.com/articles/2757235-rob-gronkowski-sa...

And furthermore, in that article Gronkowski is quoted as even preferring to take dangerous hits in the head like that, instead of risking re-injuring a bad knee. Not a great policy.