I know, it's surprising. We didn't even know they were friendly (apart from them reportedly "having history" via Freaks and Geeks).  Given the below tweet, said blocking was most surprising for Seth Rogen, who posted the following NSFW response to twitter...

The good people at Uproxx have gone through Seth's twitter feed, and might be able to enlighten the actor as to why his fellow thesp - who's currently promoting Man Down at the Venice Film Festival - took the time to block him on social media.

And if that weren't enough...

We're not entirely sure what the above tweet was in reference to, it could've been a myriad of things (Shia in the past has enjoyed lots of extracurricular past times - arse pinching at a Broadway show, running around Amsterdam tethered to people, head butting folk in London pubs, his art installations...), but even randomers on twitter knew he'd GONE TOO FAR...
 

Via Uproxx