JIDDA — Roughly two years ago, Rowdha Yousef began to notice a disturbing trend: Saudi women like herself were beginning to organize campaigns for greater personal freedoms. Suddenly, there were women asking for the right to drive, to choose whether to wear a veil, and to take a job without a male relative’s permission, all using the Internet to collect signatures and organize meetings and all becoming, she felt, more voluble by the month.

The final straw came last summer, when she read reports that a female activist in Saudi Arabia’s eastern province, Wajeha al-Huwaider, had been to the border with Bahrain, demanding to cross using only her passport, without a male chaperon or a male guardian’s written permission.

Ms. Huwaider was not allowed to leave the country unaccompanied and, like other Saudi women campaigning for new rights, has failed — so far — to change any existing laws or customs.

But Ms. Yousef is still outraged, and since August has taken on activists at their own game. With 15 other women, she started a campaign, “My Guardian Knows What’s Best for Me.” Within two months, they had collected more than 5,400 signatures on a petition “rejecting the ignorant requests of those inciting liberty” and demanding “punishments for those who call for equality between men and women, mingling between men and women in mixed environments, and other unacceptable behaviors.”