Originally Posted by SystemicAnomaly
Not really. If the foot faulting is blatant, as the OP qualified, it is not difficult at all to detect it. If it is a minor fault, then I might agree with you. With some footfaults, the server is stepping across an imaginary extension of the center mark. In this case, the serve appears to come from the wrong direction. This is also noticeable if it is blatant.
Again, I did not say it is right, I'm just saying that unless they're serving from inside the court, you really shouldn't be looking to see if your opponent's toe is on the line. If you're playing doubles, as I said, then that's fine as when you're not returning, you can easily see. If your opponent is serving on the hash mark, then again, that's quite obvious. I'm talking about stepping on the line or toeing the line. If it's a league match and it's quite obvious, a simple "hey, you're foot faulting when you step up to the line, you might want to take a step back" on a changeover is all it takes.
There is even a guy at our local tennis center who does footfault religiously. He's inside the baseline when he makes contact and it's quite funny. He doesn't play in leagues, only friendly pickup matches, and not a single person has complained even though it's blatant. Why? It just doesn't matter when you're playing a 65 year old guy who doesn't go out and work on his technique like younger players do. Just enjoy returning serve and focus on other things.