These people are protesting abortion by praying outside of clinics where people risk their lives every day to help women that are desperately in need of counseling and service.
If they really cared about abortion they would be in schools providing sex education or lobbying for more government support of programs that distribute birth control.
But wait, they are against those things too.
Even pro-lifers think you should avoid abortion at all costs. However, whether you are for or against abortion, it is best to strike at the root of the problem instead of complaining about the problem itself. And of course, making things worse by preaching abstinence only education and prohibiting birth control is not going to make abortion go anywhere anytime soon.