In its latest attempt to clean up the messages being sent across its site, Twitter is now letting users flag spammers by clicking a “report as spam” button on their profiles. Twitter says a team of employees will follow up on the reports. Previously, users could only call attention to spam by direct messaging an @spam account. This follows an earlier initiative by the microblogging service to filter out links which directed users to known malware sites. Both moves come as spammy Twitter accounts have become a problem for the site. According to a recent report, about 3.75 percent of all Tweets are spam; anecdotal accounts suggest that the amount of spam on the site may in fact be higher and could be turning some users away.