Let zeta-1 be the critical exponent associated with the probability that l independent N-step ordinary random walks, starting at nearby points, are mutually avoiding. Using Monte Carlo methods combined with a maximum-likelihood data analysis, we find that in two dimensions zeta-2 = 0.6240 +/- 0.0005 +/- 0.0011 and zeta-3 = 1.4575 +/- 0.0030 +/- 0.0052, where the first error bar represents systematic error due to corrections to scaling (subjective 95% confidence limits) and the second error bar represents statistical error (classical 95% confidence limits). These results are in good agreement with the conformal-invariance predictions zeta-2 = 5/8 and zeta-3 = 35/24.