Curity/social order/traditional values Motive: Independence/self-determination Motive: Increasing life quality and competence Topic: Art/culture/education Topic: Economics Topic: GDC-0084 biological activity Politics Topic: Media Topic: Environmental and animal welfare Constant Number of observations Number of groups R-square (between) Wald chi2 Legend < p .1 *< p .05 **< p .01 ***< p .001 doi:10.1371/journal.pone.0155923.t001 .00 .00 .00 .03 .01 .00 .05 .00 -.01 .01 .00 -.06 -.01 .02 .00 .05 .05 .06 .00 .00 .00 .01 .01 .01 .01 .00 .01 .01 .01 .01 .01 .01 .01 .01 .01 .02 114.09 -3.31 -.35 3.38 .71 -.38 4.03 -5.69 -1.28 1.29 .05 -8.65 -1.25 1.97 .13 4.01 4.37 3.88 532196 1568 12.69 15031.07 *** *** *** *** * *** *** *** ** *** ** Coef. -.02 .04 .02 .01 Std.Err. .00 .01 .01 .00 z -13.10 4.45 2.16 12.17 P>|z| *** *** * *** Model 2 Coef. .00 .05 .03 .02 -.02 -.01 -.01 .00 .00 .00 .03 .01 .00 .05 .00 -.01 .01 .00 -.06 -.01 .02 .00 .05 .05 .06 Std.Err. .00 .01 .01 .00 .01 .00 .00 .00 .00 .00 .01 .01 .01 .01 .00 .01 .01 .01 .01 .01 .01 .01 .01 .01 .02 z -.35 4.86 2.38 12.15 -3.01 -3.00 -3.19 114.13 -3.30 -.33 3.39 .70 -.43 4.03 -5.68 -1.30 1.29 .05 -8.69 -1.26 1.98 .15 4.01 4.40 3.70 532196 1568 12.70 15066.10 *** *** *** *** * *** *** *** *** *** * *** ** ** ** *** ** P>|z|PLOS ONE | DOI:10.1371/journal.pone.0155923 June 17,12 /Digital Norm Enforcement in Online FirestormsTable 2. Predicted amount of online aggression dependent on the anonymity of aggressors (fixed-effects regression). Model 1 Y: Amount of online aggression (log) Anonymity Controversy of accusation Accusation is connected to a scandal Intrinsic motivation (log) Anonymity x Controversy Anonymity x Scandal Anonymity x Intrinsic motivation Length of comment in words Time of comment after petition opening Number of protest participants (log) Status of the accused (log) Scope of protest Success of the petition Accused is a natural person (vs. legal entity) Anonymity of social environment of aggressors (log) Motives: Income/minimization of costs Motive: Security/social order/traditional values Motive: Independence/self-determination Motive: Increasing life quality and competence Topic: Art/culture/education Topic: Economics Topic: Politics Topic: Media Topic: Environmental and animal welfare Constant Number of observations Number of groups R-square (PD98059 biological activity within) F-value Legend < p .1 *< p .05 **< p .01 ***< p .001 doi:10.1371/journal.pone.0155923.t002 .00 .00 .00 (drop.) (drop.) (drop.) (drop.) .00 (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) .11 .00 33.16 532196 1568 2.70 2449.47 *** *** .00 -5.79 *** .00 .00 .00 114.00 -3.63 -.31 *** *** Coef. -.02 (drop.) (drop.) .01 .00 11.79 *** Std.Err. .00 z -13.14 P>|z| *** Model 2 Coef. .00 (drop.) (drop.) .02 -.02 -.01 -.01 .00 .00 .00 (drop.) (drop.) (drop.) (drop.) .00 (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) .11 .00 32.90 532196 1568 2.70 1636.62 *** *** .00 -5.77 *** .00 .01 .00 .00 .00 .00 .00 11.82 -3.07 -3.00 -3.18 114.04 -3.64 -.29 *** ** ** ** *** *** Std.Err. .00 z -.29 P>|z|Model 1, preliminarily support Hypothesis 3: online aggression is encouraged by intrinsically motivated actors as compared to individuals without fairness concerns (for the size of the effects see Figs 4 and 5). Building on the view that social media today are a major channel for digital social norm enforcement, which until now is not rejected by the data, Hypothesis 4 assumes that online aggression takes place non-anonmously. Agg.Curity/social order/traditional values Motive: Independence/self-determination Motive: Increasing life quality and competence Topic: Art/culture/education Topic: Economics Topic: Politics Topic: Media Topic: Environmental and animal welfare Constant Number of observations Number of groups R-square (between) Wald chi2 Legend < p .1 *< p .05 **< p .01 ***< p .001 doi:10.1371/journal.pone.0155923.t001 .00 .00 .00 .03 .01 .00 .05 .00 -.01 .01 .00 -.06 -.01 .02 .00 .05 .05 .06 .00 .00 .00 .01 .01 .01 .01 .00 .01 .01 .01 .01 .01 .01 .01 .01 .01 .02 114.09 -3.31 -.35 3.38 .71 -.38 4.03 -5.69 -1.28 1.29 .05 -8.65 -1.25 1.97 .13 4.01 4.37 3.88 532196 1568 12.69 15031.07 *** *** *** *** * *** *** *** ** *** ** Coef. -.02 .04 .02 .01 Std.Err. .00 .01 .01 .00 z -13.10 4.45 2.16 12.17 P>|z| *** *** * *** Model 2 Coef. .00 .05 .03 .02 -.02 -.01 -.01 .00 .00 .00 .03 .01 .00 .05 .00 -.01 .01 .00 -.06 -.01 .02 .00 .05 .05 .06 Std.Err. .00 .01 .01 .00 .01 .00 .00 .00 .00 .00 .01 .01 .01 .01 .00 .01 .01 .01 .01 .01 .01 .01 .01 .01 .02 z -.35 4.86 2.38 12.15 -3.01 -3.00 -3.19 114.13 -3.30 -.33 3.39 .70 -.43 4.03 -5.68 -1.30 1.29 .05 -8.69 -1.26 1.98 .15 4.01 4.40 3.70 532196 1568 12.70 15066.10 *** *** *** *** * *** *** *** *** *** * *** ** ** ** *** ** P>|z|PLOS ONE | DOI:10.1371/journal.pone.0155923 June 17,12 /Digital Norm Enforcement in Online FirestormsTable 2. Predicted amount of online aggression dependent on the anonymity of aggressors (fixed-effects regression). Model 1 Y: Amount of online aggression (log) Anonymity Controversy of accusation Accusation is connected to a scandal Intrinsic motivation (log) Anonymity x Controversy Anonymity x Scandal Anonymity x Intrinsic motivation Length of comment in words Time of comment after petition opening Number of protest participants (log) Status of the accused (log) Scope of protest Success of the petition Accused is a natural person (vs. legal entity) Anonymity of social environment of aggressors (log) Motives: Income/minimization of costs Motive: Security/social order/traditional values Motive: Independence/self-determination Motive: Increasing life quality and competence Topic: Art/culture/education Topic: Economics Topic: Politics Topic: Media Topic: Environmental and animal welfare Constant Number of observations Number of groups R-square (within) F-value Legend < p .1 *< p .05 **< p .01 ***< p .001 doi:10.1371/journal.pone.0155923.t002 .00 .00 .00 (drop.) (drop.) (drop.) (drop.) .00 (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) .11 .00 33.16 532196 1568 2.70 2449.47 *** *** .00 -5.79 *** .00 .00 .00 114.00 -3.63 -.31 *** *** Coef. -.02 (drop.) (drop.) .01 .00 11.79 *** Std.Err. .00 z -13.14 P>|z| *** Model 2 Coef. .00 (drop.) (drop.) .02 -.02 -.01 -.01 .00 .00 .00 (drop.) (drop.) (drop.) (drop.) .00 (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) (drop.) .11 .00 32.90 532196 1568 2.70 1636.62 *** *** .00 -5.77 *** .00 .01 .00 .00 .00 .00 .00 11.82 -3.07 -3.00 -3.18 114.04 -3.64 -.29 *** ** ** ** *** *** Std.Err. .00 z -.29 P>|z|Model 1, preliminarily support Hypothesis 3: online aggression is encouraged by intrinsically motivated actors as compared to individuals without fairness concerns (for the size of the effects see Figs 4 and 5). Building on the view that social media today are a major channel for digital social norm enforcement, which until now is not rejected by the data, Hypothesis 4 assumes that online aggression takes place non-anonmously. Agg.