Sorry, I am late posting this as they are looking for signatures by tomorrow (though possibly even late signatures are helpful). This is the link to the petition (and suggested other actions) standwithsaudifeminists.org/take-action/
and this is the background information (feminists are being targetted there, unsurprisingly):
"After nearly three decades of struggle for women’s rights as well as feminist campaigning in Saudi Arabia, the ban on women driving will be lifted on June 24, 2018. ...
As June 24 approached, and excitement inside the country became palpable, Saudi authorities cracked down on feminist activists and campaigners, both women and men, who have led the fight for the basic right to drive a car. Some were rounded up and thrown in jail on May 15 while others were placed under a travel ban shortly after. Another wave of arrests followed on June 6, adding to the precarity that Saudi Arabian citizens have to endure. "
More info standwithsaudifeminists.org/