I hear people say things like this all the time. What does it really mean? Do you believe that politicians are bribed with big cases of money? Or are you referring to campaign contributions?
I would probably attribute it to agents wanting to further their careers by catching some people and getting them convicted. All of the agent's office buddies are going after copyright violators, so they do too.
Generally what is meant by "bribe politicians" is twofold. The first aspect is campaign contributions, which help keep the politician in office. But the second one is post-legislature work. A former Senator just got made MPAA head, and similar things happen throughout the business sector - get defeated in the polls (or don't run for reelection) and move over to a cushy job on a corporate board or as figurehead of an industry group, where you get paid a 6-figure sum for easy and part-time work. Both of these are perfectly legal if unseemly.
I agree that it may also be about agents who want to further their careers - because the punishments for copyright violation are so high, it probably looks just as good on the CV as a successful DDOS or spam case, and it's probably markedly easier.
I would probably attribute it to agents wanting to further their careers by catching some people and getting them convicted. All of the agent's office buddies are going after copyright violators, so they do too.