SANTA CLARA -- Running back Brandon Jacobs went to Twitter the day after sustaining an injury to inform his 16,000 followers he received good news after an MRI examination.The previous night after going down with a left knee injury against the Houston Texans, Jacobs, whose Twitter name is @gatorboy45, received a lot of tweets. Most of the contact he received from fans was positive.But Jacobs also re-tweeted five hateful messages he received anonymously -- each of which contained offensive words.Some of the messages questioned his manhood. Some took delight in seeing Jacobs get injured. Some expressed both sentiments.I asked Jacobs on Tuesday why he decided to share those comments?"Everybody thinks this life is all easy and you got to deal with nothing," Jacobs explained. "I like for people to see what else is out there, what else we deal with as NFL players. Let them see what it is that we go through."One person said, 'I hope you die a horrible death.' I tweeted him back saying, 'I'm sure my wife and my kids appreciate that. Have a good day.' It's stuff like that, it's uncalled for. There are some real dumb, stupid people out there."Jacobs previously was on Twitter but closed his account last season when he was going through some frustrating times with the New York Giants. He began a new account in May.Ultimately, Jacobs said he likes having the tools to connect with his followers. He also regularly posts photos on Instagram under the name @bigone45."There's no point having it if you're not going to connect with people," Jacobs said. "Twitter is a good way to communicate with your fans in a positive way."But it's also a great method for weak, heartless cowards. There are a lot of those people out there. It's more funny to me than anything to know there are stupid, dumb people out there like that. I deal with it and move on with my day.Jacobs said most of the feedback and interaction with fans is good-natured and positive. But he is also conditioned to expect everything."I've gotten great support from Giants fans," he said. "I've gotten negative from Giants fans. I've gotten great support from San Francisco fans. And I've gotten some negative from San Francisco fans, as well."I was on Twitter once before because I didn't know how to handle it. But I figured a way to handle it now, and I like it. . . I'm a little smarter. The people don't ruin my day, by any means. I just deal with it." Jacobs, who was on crutches for most of last week, is clearly moving a lot better. There is still a chance he could be available for the 49ers' regular-season opener Sept. 9 against the Green Bay Packers.