Firstly you would need to define what sort of behaviour that should be covered by 'strict liability' but as long as its kept at a high level then this shouldnt be to difficult.
Throwing bottles, individual or group pitch invasions, attacking refreees, acts of damage in the stadium, racism , gender abuse and obvious sectarianism seem easy to identify and the layout of football grounds means its also very obvious who the culprit or culprits were.
Taking recent examples unfortunately involving us and you have an individual Hibs fan who threw a bottle and a Hibs fan who invaded the pitch and accosted a 'Scotlands Shame 2012' player both incidents clearly from the Hibs part of the stadium.
A 'Celtc' fan also threw a bottle and a 'Scotlands Shame 2012' creature chucked a seat and collectively 'Scotland's Shame 2012' fans and Celtc' fans damaged the Hibs stadium and again collectively both were involved in odius sectarian singing and all of this was without question emanating en masse from the away end of the stadium.
With strict liability clubs would be forced to take responsibility for the action of their fans either individually or collectively and therefore Hibs, Celtc and 'Scotlands Shame 2012' would now be looking at the following list of sanctions:
Hibs: Warnings and fines and partial stadium closure.
Celtc: Fines and a ban on selling tickets to away fans.
'Scotlands Shame 2012': Fines, ban on selling away tickets, play all matches in a third country, deduction of all points and subsequent withdrawl of its football licence leading to its non existence as a football club
Use some sort of totting up system over a season or season(s) and clubs across Scotland would face the threat of a points deduction, playing matches behind closed doors or full or partial stadium closure for a defined length of time.
'Strict liability' wouldnt elimate extreme offensive behaviour at football matches but it would reduce the incidents as it would focus minds of the clubs who would then do far more to control their fan base collectively and supporters would self police more and at least indicate to the bam element that they are not welcome or wanted.
Individual supporters going along to games and getting themselves arrested, and fined and then facing lifetime banning orders just to 'getitrightup' their rivals wont happen and would be far to obvious to be effective and very easy for the authorities to identify.