Twitter said Monday it is backing a bill to require more disclosures around online political ads, after facing pressure following Facebook's endorsement.

The bigger picture: The endorsements show the web companies still dealing with the fallout of manipulation of their platforms during the 2016 elections are becoming increasingly willing to work with policymakers on new rules.

• The bill hasn't gained much momentum since being introduced last fall, so it's unlikely to pass anytime soon.
• Google has not yet endorsed the bill, despite pressure from Sens. Mark Warner and Amy Klobuchar.