How to deal with passive winners?

[Cerril]

Okay, I know they're playing suboptimally and if I improve and beat them they get crushed, but I'm curious if there's something else I should be doing. Here's the general case:

Passive player plays a moderately too loose selection of hands (between 30-55%), almost never raises preflop (anything from only top PPs to never) will play some draws but usually only made hands. He's not a rock though, and will certainly call down with losing hands. He'll also tend to check/call down TPTK, 2p, trips, sets, and just about anything. In fact, you're not sure you've ever seen him raise.

Does this guy (and I think I'm describing a player type we've all played against) deserve any special treatment? He's never worth too many bets when you win, and he'll end up sucking more bets out of you when he wins than many other players.

In fact, that's the primary reason I'm asking - unintentionally, he ends up playing shockingly well against your marginal holdings - he'll check/call down against your bets with top pair, moderate kicker (ATs say) and then turn over two pair or AQ or something else almost anyone would have bet or raised with. You'd have been glad to have folded but instead you end up betting to the end with pretty good confidence you're way ahead in the hand.

Or am I just too worried about something that happens too infrequently?