The anonymous congressional staff members who write the nation’s laws generally work hard for fairly modest wages. Increasingly, though, they do so because there is a promise of K-Street riches at the end of their toil.

A new study by the Sunlight Foundation found that the number of active lobbyists with prior government experience has nearly quadrupled since 1998, rising to 1,846 in 2012. Those revolving-door lobbyists, mostly from Capitol Hill, accounted for nearly all of the huge growth in lobbying revenue during that period, which increased to $1.32 billion from $703 million in 1998.

A New York Times article on Sunday showed that many of those former staff members are violating the intent of a 2007 law that requires a waiting period before former congressional employees can lobby Congress. The law imposes a one-year ban for senior staff and House members, and two years for senators, but some House staff members are deliberately keeping their salaries low so they won’t be considered “senior” and can lobby right away. Others use a loophole to claim that they can lobby a committee right away, because they technically worked for an individual lawmaker and not the committee.

Some of those who are lobbying or working for corporate clients are actually former lawmakers. Joe Baca, a former Democratic congressman from California, introduced a bill when he was in the House that would have reduced oversight of payday lenders, notorious for exploiting desperate low-income people. Then, after he left the House, the payday lending industry hired him to run its lobbying organization. (He is now running for re-election, adding gall to his spin through the door.)